International Building Code Illustrated Handbook 2015 International Code Council

The primary goal of Chapter 17 of the International Building Code® (IBC®) is to improve the quality and workmanship of certain structural systems by requiring structural testing, special inspection, and structural observation. Many of the requirements are specifically intended to improve the quality of the lateral-force-resisting system when buildings are subjected to the design wind or seismic event. To accomplish these goals, the chapter sets forth provisions for quality of materials, workmanship, testing, and labeling of materials incorporated into the construction of buildings or structures regulated by the code. Generally, all components and materials used in new buildings must conform to the requirements in the code, or the applicable standards referenced by the code.* Specific tests and standards are referenced in other parts of the code. Chapter 35 contains a complete alphabetical list of all the testing and material standards referenced in the IBC.

This chapter provides the requirements for special inspection and verification of the construction at various stages, special inspection for wind and seismic resistance, special testing and qualification for seismic resistance, structural observation by the registered design professional, and alternative methods to establish test procedures for products that do not have applicable standards.

From a historical perspective, several successful code changes to Chapter 17 of the 2009 IBC clarified the provisions to make them more useable. Further reorganization and consolidation was done in the 2012 and 2015 IBC, which will be discussed in some detail in the appropriate section.

Because Chapter 18 was revised entirely in the 2009 IBC, editorial changes were made to the special inspection provisions for soils, driven deep foundations, cast-in-place deep foundations, helical pile foundations, and vertical masonry foundation elements. Helical pile foundations, which were added to Chapter 18 in the 2009 IBC, require continuous special inspection during installation.

The most significant change to Chapter 17 in the 2012 IBC was the reorganization of provisions pertaining to special inspection, the statement of special inspections, contractor responsibility, structural observations, and required verifications. All of the administrative requirements related to special inspection, the statement of special inspections, contractor responsibility, and structural observations, are now contained in Section 1704. All of the verifications required for various systems, elements, and materials, including special inspection requirements for wind and seismic, are now contained in Section 1705. In the 2009 IBC, Section 1704 covered what specific items required special inspection, and Section 1705 covered what is required to be included in the statement of special inspections. There were a variety of conflicts and inconsistencies between the two sections. The charging sentence of Section 1705 stated that where special inspection or testing was required by Section 1704, 1707, or 1708, the registered design professional in responsible charge must prepare a statement of special inspections in accordance with Section 1705. For example, suspended ceilings in Seismic Design Category D are required to be included in the statement of special inspections, yet Sections 1704, 1707, and 1708 did not specifically require special inspection for suspended ceilings. Additionally, items that required special inspection or testing by Section 1704, 1707, or 1708 were not all covered in the requirements for the statement of special inspections in Section 1705. In other words, not all items that require special inspection under Section 1704, 1707, or 1708 were listed in Section 1705, and not all items required to be in the statement of special inspection in Section 1705 require special inspection in Section 1704, 1707, or 1708. To resolve these issues, the special inspection and statement of special inspections provisions were reorganized in the 2012 IBC in an effort to clarify the intent and improve proper application and enforcement.

Section 1701 General

This section sets forth the scope for Chapter 17 and the general requirements for both new and used construction materials. Because Chapter 17 deals with construction documents and submittals, some discussion of the subject is warranted. The term construction documents is defined in Section 202 as “written, graphic and pictorial documents prepared or assembled for describing the design, location and physical characteristics of the elements of a project necessary for obtaining a building permit.” Construction documents are a part of the submittal documents required by Section 107. It should be noted that there are also specific requirements for construction documents in Section 1603 for structural loads, as well as in the structural material chapters, such as Section 1901.5 for concrete structures. There are also requirements for specific types of submittals, which are considered part of the construction documents. For example, Section 1803.6 for geotechnical reports, Section 2207.4 for steel joist drawings, Section 2211.3.1 for cold-formed steel truss drawings, and Section 2303.4.1.1 for wood truss drawings.

1701.2 New materials. Testing is required for all materials that are not specifically provided for in the code or referenced standard. For example, a composite wood material that is not listed in Chapter 23 would be required to follow the procedures set forth in this chapter. A similar provision for acceptance of alternative materials, systems, or methods for which the standards are not adopted in the code is set forth in Section 104.11. This section restates that alternative or new materials and methods may be used if it can be established by tests or other means that the performance of the new material or method will equal that required by the code for the replaced product. As noted, ICC Evaluation Service Reports are often used by building officials as the basis for approving items that are not specifically addressed by the code or referenced standards.

Used materials. The section on used materials was deleted in the 2015 IBC because the requirements are already covered by Section 104.9.1. Materials may be reused, provided they meet all the code requirements for new materials. Note, however, that Section 104.9.1 specifically restricts the use of used equipment and devices unless approved by the building official. One should always exercise caution in approving reuse of materials. The applicable material or design standards should be consulted to determine if reuse of materials is allowed or prohibited. For example, reuse of high-strength A490 structural bolts is prohibited by the AISC RCSC¹ specifications. Even a piece of used structural steel should be carefully checked for conformance to the design specifications, applicable standards, and code requirements.

Section 1702 Definitions

1702.1 General. Definitions of various terms help in the understanding and application of code requirements. A list of the terms used in Chapter 17 that are defined in Chapter 2 is provided in this section so that the reader is aware of specific terminology used in Chapter 17. The actual definitions are provided in Section 202.

APPROVED AGENCY. The definition of this term is needed in order to effect the requirements of Section 1703.1. The word approved means “acceptable to the building official or authority having jurisdiction” (see the definition of approved in IBC Section 202). The basis for approval of an agency for a particular activity by the building official includes the competence or technical capability to perform the work in accordance with Section 1703.

APPROVED FABRICATOR. An approved fabricator is a qualified person, firm, or corporation that is approved by the building official to perform specified work without special inspection because they have approved quality-control procedures and are subject to periodic auditing of fabrication practices by an approved special inspection agency. Approved fabricators issue certificates of compliance for their work product. See discussion of Section 1704.2.5.

CERTIFICATE OF COMPLIANCE. An approved fabricator is required to submit a Certificate of Compliance for work performed without special inspection. See Section 1704.2.5 for more detailed discussion of fabricator approval. Figure 1703-3 shows an example of an AITC certificate of compliance for a glue-laminated timber.

DESIGNATED SEISMIC SYSTEM. The designated seismic system consists of those architectural, electrical, and mechanical systems and their components that require design in accordance with Chapter 13 of ASCE 7 for which the component importance factor, I_p, is greater than 1.0, as prescribed in Section 13.1.3 of ASCE 7. Section 13.1.3 of ASCE 7 lists four components that have an importance factor of 1.5, which include components required to function after an earthquake including fire sprinkler systems and egress stairways that are not an integral part of the building structure; components containing hazardous, toxic, or explosive materials; and components in Risk Category IV structures that are necessary for continued operation of the facility. All other components are assigned a component importance factor of 1.0. Risk Category IV structures are described in detail in IBC Table 1604.5. Note that Section 13.1.4 of ASCE 7 lists those nonstructural components that are exempt from the seismic design requirements of Chapter 13 and are therefore not considered to be part of the designated seismic system.

FABRICATED ITEM. Fabricated items are materials assembled prior to installation in a building and are referred to in Section 1704.2.5. The definition is provided to clarify the intent of the code, as the term fabricated items could easily be interpreted to mean items for which special inspection is not intended by the code. An example of a fabricated item for which special inspection is required is roof trusses not manufactured in accordance with the in-plant quality control requirements of the TPI 1 standard. The section also describes elements that are not considered fabricated items, such as rolled structural steel, reinforcing bars, masonry units, and wood structural panels that are fabricated under specific quality control standards. Because special inspections are analogous to the quality control (QC) programs required by some standards referenced in the code, a change in the 2009 IBC was made that items produced in accordance with standards listed in Chapter 35 that have quality control by a third-party quality-control agency are not considered “fabricated items.” This change makes it clear that the code does not intend to impose a redundant special inspection requirement for such items.

MAIN WIND-FORCE-RESISTING SYSTEM. The main wind-force-resisting system (MWFRS) is one of the structural systems that must be designed to resist wind loads. The other system that is designed to resist wind loads is components and cladding. The MWFRS comprises those structural elements that provide lateral support and stability for the overall structure. In general, these are out-of-plane walls, diaphragms, chords, collectors, vertical lateral-force-resisting elements such as shear walls, braced frames, and so on, and foundations. In general, the MWFRS receives wind loading from more than one surface. In contrast, components and cladding are generally on the exterior envelope of the building and receive loading directly from the wind, such as roof and wall covering.

SPECIAL INSPECTION. That category of field inspection for which special knowledge, special attention, or both are required. For example, inspection of complete penetration welds requires both special knowledge and special attention to ensure that the requirements of the codes and standards are met. Note that the special inspector does not have the same authority as that of the jurisdiction inspector. The role of the special inspector is to report discrepancies between the construction in the field and the approved construction documents to the contractor. If uncorrected, discrepancies should be reported to the design professional in responsible charge and to the building official.

SPECIAL INSPECTION, CONTINUOUS. Continuous full-time inspection is required where compliance of the work or product cannot be determined after incorporation into the building or structure. For example, one cannot determine whether a multipass fillet weld is in compliance with the code requirements unless each pass of the weld is inspected during the welding process. Whether a particular special inspection is continuous or periodic is specified in the various inspection and verification tables in Section 1705.

SPECIAL INSPECTION, PERIODIC. Intermittent or part-time inspection, which may be allowed when the compliance of the work or product can be determined after being incorporated into the structure. For example, compliance with the design nailing requirements of a wood shear wall can be determined after construction of the wall (but before closure); hence, verification by periodic special inspection is adequate in this case. Another good example is placement of reinforcing bars. The special inspector need not be continuously present during placement. Whether a particular special inspection is periodic or continuous is specified in the various inspection and verification tables in Section 1705.

STRUCTURAL OBSERVATION. Structural observation is intended to ensure general conformance with the design intent, and not necessarily specific conformance with the code. For example, in a building under construction in a high seismic area, the registered design professional acting as the structural observer may focus on crucial elements of the seismic-force-resisting system. Like the special inspector, the structural observer does not have the same authority as that of the jurisdiction inspector. The role of the structural observer is to report discrepancies between the construction in the field and the approved design documents to the contractor. If unresolved, discrepancies should be reported to the building official. Note that structural observation by the registered design professional does not replace or substitute for any of the requisite special inspections required by Section 1705 or the jurisdiction inspections required by Section 110.

Several definitions that were previously in Section 1702 were deleted in the 2009 IBC and relocated to Section 202 because these terms are more general in nature. Some definitions have been deleted entirely in each subsequent edition of the IBC because they are no longer relevant or are covered in a referenced standard. As noted, all definitions in the 2012 IBC are now found in Section 202 only.

Section 1703 Approvals

1703.1 Approved agency. The word approved means “acceptable to the building official or the authority having jurisdiction” (see the definition of “Approved” in IBC Section 202.1). The basis for approval of an agency for a particular activity by the code or building official may include the capacity or technical capability and expertise necessary to perform the work in accordance with Section 1703. Special inspection agencies, testing laboratories, and the inspection agencies that provide quality assurance of concrete and steel fabricators should be accredited by a recognized Accreditation Body. For example, testing laboratories should be accredited to ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories.

Accreditation through the International Accreditation Service (IAS), a subsidiary of the International Code Council (ICC), is the most straightforward method for the building official to assure that an agency provides quality services and meets all of the requirements of the building code. Quality standards for agency approvals through IAS are defined by the following standards:

• Special inspection agencies should be accredited to IAS AC291.

• Fabricators of reinforced and precast/prestressed concrete should be inspected by an approved special inspection agency, or by an inspection agency, which is accredited to IAS AC157.

• Fabricators of structural steel should be inspected by an approved special inspection agency, or by an inspection agency, which is accredited to IAS AC172.

• Fabricators of metal building systems should be inspected by an agency, which is accredited to IAS AC472.

• Fabricators of cold-formed steel structural and nonstructural components not requiring welding should be inspected by an agency, which is accredited to IAS AC473.

Other accreditation programs are also available that may be approved by the building official, such as the AISC Certification Program for Structural Steel Fabricators, the Plant Certification Program for steel joists by the Steel Joist Institute, or the Plant Certification Program for precast concrete products by the Precast/Prestressed Concrete Institute.

Accreditation helps to ensure that the agency has the necessary equipment and employs qualified persons. For example, if an agency wishes to be approved for the special inspection of structural welds, the agency should submit evidence that its welding inspector is certified in accordance with applicable International Code Council (ICC), American Welding Society (AWS), or American Society of Nondestructive Testing (ASNT) requirements.

1703.1.1 Independence. The agency should have objectivity as well as competence. Objectivity can be measured by the agency’s financial and fiduciary independence. The agency should be independent from the contractor responsible for the work and have no financial ties to the organization it inspects. For example, a testing laboratory checking concrete strength should have no financial ties to the contractor, its subcontractors, or the concrete supplier.

1703.1.2 Equipment. If any agency is not accredited as described above, the building official should evaluate the agency to confirm compliance with the requirements of applicable standards and that it has the appropriate equipment to perform required tests or inspections.

1703.1.3 Personnel. If the agency is not accredited, the building official should evaluate both the experience and qualifications of personnel. An agency may have personnel with the appropriate certifications but not the necessary experience. Supervisory and inspection personnel should have the appropriate certifications as well as the requisite experience and/or education.

If the services being provided by an inspection or testing agency come under the purview of the professional registration laws of the state or jurisdiction, the building official should request evidence that personnel are qualified to perform the work in accordance with the requisite professional registration.

1703.2 Written approval. A written approval by the building official is required for all material, appliances, equipment, or systems incorporated into the work in order to have a documented record of approval and the basis for approval.

1703.3 Record of approval. Records must be kept for all approvals, including conditions and limitations of approval. The approvals must be kept on file and available for public inspection. The records must demonstrate compliance with the applicable code requirements of any material, appliance, equipment, or system incorporated into the structure.

1703.4 Performance. When conformance with the code is predicated on the performance and quality of materials or products, the building official must require the submission of test reports from an approved agency establishing this conformance. In the absence of such reports, the building official should require specific data that show compliance with the intent of the applicable code requirements in accordance with Chapter 16 (see IBC Sections 1604.6 and 1604.7). For example, core tests of in situ concrete could be used to determine compliance with design strength if the sample cylinders required by ACI 318² were destroyed.

Materials and products must be subjected to various levels of quality control and identification in order to determine that the material complies with the requirements of the code. The degree of quality control and identification to which a material must be subjected is based on its relative importance to the structure’s performance and function. See Section 202 for definitions of the terms mark, manufacturer’s designation, label, and certificate of compliance. By use of these terms, the code establishes a hierarchy of quality control and identification as follows:

Level 1: Manufacturer identifies the material or product with the name of the material or product, the manufacturer’s name, and the intended usage (see Mark).

Level 2: Manufacturer identifies the material or product as in Level 1 and also certifies compliance with a given standard or set of rules (see Manufacturer’s designation).

Level 3: Manufacturer identifies the material or product as in Level 1. An approved quality control agency performs periodic audits of the manufacturer’s facilities and QA/QC procedures.

Level 4: Each batch of material or individual product is inspected by an approved quality control agency (see Certificate of Compliance).

The term mark is an identification applied on a product by the manufacturer indicating the name of the manufacturer and the function of a product or material. An example of the APA trademark for rated wall sheathing is shown in Figure 1703-1.

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Figure 1703-1 APA-rated sheathing.

The term manufacturer’s designation refers to an identification applied on a product by the manufacturer indicating that a product or material complies with a specified standard or set of rules. An example of a manufacturer’s designation would be the designation on ASTM A706 reinforcing bars where the “W” indicates the bars conform to the ASTM A706 standard for weldable rebar. See Figure 1703-2.

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Figure 1703-2 Required marking for ASTM A706 (weldable) reinforcing bars.

The term Certificate of Compliance refers to an identification applied to a product by an approved agency containing the name of the manufacturer, the function, and the performance characteristics, and indicates that the product or material has been inspected and evaluated by an approved agency. An example of an inspection certificate would be a Certificate of Conformance for a glue-laminated beam that meets the ANSI/AITC A190.1 specification. The specification requires that each glue-laminated timber be marked with the AITC Quality Mark (see “Mark”) or be accompanied by an AITC Certificate of Conformance. Where appearance is important, such as exposed glue-laminated beams, a certificate of conformance is used. See Figure 1703-3.

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Figure 1703-3 Certificate of Conformance for a glue-laminated beam.

1703.4.1 Research and investigation. This section is intended to implement the requirements of Section 104.11 for use of innovative or alternative materials, design, and methods of construction. For example, an innovative prestressed concrete system that does not emulate the performance of cast-in-place concrete could be evaluated in accordance with this section. Note that the section requires that the costs of collecting data and preparing reports are to be borne by the applicant.

1703.4.2 Research reports. This section is identical to Section 104.11.1 regarding the use of innovative or alternative materials, design, and methods of construction. Evaluation reports prepared by approved agencies, such as those published by the organizations affiliated with the model code groups, may be accepted as part of the data needed by the building official to form the basis of approval of a material or product not specifically covered by the code. ICC Evaluation Service Reports are considered by many building officials to be the most straightforward method for the building official to review products and systems that are not specifically covered by the code. Such reports supplement the resources of the building official and eliminate the need for the official to conduct detailed analysis on every new product that is not covered by the code or a referenced standard. Because evaluation reports issued by the model code-affiliated organizations are advisory in nature, the building official is not mandated to accept or approve them. Technically, such products and reports are approved under the alternative materials and methods of construction provisions of Section 104.11.

1703.5 Labeling. When materials or assemblies are required to be labeled by the code, such as wood structural panels, rated sheathing, lumber, fire doors, and so on, the labeling must be in accordance with the procedures outlined in this section and its subsections. Labeling of materials or assemblies is an indication that the materials or assemblies have been subjected to testing, inspection, and/or other operations by the labeling agency. The presence of a label does not necessarily indicate compliance with code requirements. For example, use of plywood siding, although labeled, would not comply with the code if Structural I sheathing was specified to resist the design lateral forces. The installation of labeled products must comply with the specific requirements and limitations of the label. For example, the actual span in the field for wood structural panel roof sheathing must meet the panel span rating shown on the label (stamp). See Figure 1703-4 for examples of typical lumber grade labels. Another example is a fire-rated door that is labeled with the hardware requirements specified on the label. The building inspector must ensure that the hardware used in the installation of the door meets the labeling requirements to ensure that the door complies with the code.

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Figure 1703-4 Examples of lumber grade labels.

See Section 202 for the definition of the terms label and labeled.

1703.5.1 Testing. For a material or product to be labeled, the labeling agency is required to perform specific testing on representative samples of the material or product in accordance with the applicable standards referenced by the code. For example, quality-control testing for strength and stiffness of machine stress-rated lumber to ensure that the products meet structural requirements in accordance with the American Lumber Standard system. Another example is factory-built fireplace assemblies that must be tested in accordance with the requirements of UL 127 (see Chapter 35).

1703.5.2 Inspection and identification. The approved agency whose label is applied to a material or product must perform periodic inspections of the manufacture of the material or product to determine that the manufacturer is indeed producing the same material or product as tested and labeled. For example, if the labeling agency had tested ½-inch C-C plywood sheathing made with five plies but the manufacturer was now making the plywood with only three plies, the agency would need to withdraw the use of its label and listing.

1703.5.3 Label information. This section specifies the minimum information necessary on a label for the building inspector to determine that the installed material conforms to the approved plans. See Figure 1703-4 as an example of typical lumber grade labels. Figure 1703-5 shows an actual label for APA Performance Rated Panel. The manufacturer (Georgia Pacific), the performance characteristics (Span Rating 40/20, Exposure 1), and approved agency (APA—The Engineered Wood Association) are shown.

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Figure 1703-5 APA Performance Rated Panel label.

1703.5.4 Method of labeling. This new section in the 2012 IBC was added to specify that labels that are required to be permanent must be of a nature that once applied, their removal would cause the label to be destroyed. Examples of labels that are required to be permanent are fire-resistive glazing and opening protectives.

1703.6 Evaluation and follow-up inspections. This provision applies where a structural component cannot be inspected after completion of a prefabricated assembly. An example might be a prefabricated shear wall consisting of wood structural panel sheathing over a welded steel frame; the welding must be inspected prior to the installation of the sheathing and the entire assembly must be inspected after it is fabricated. The testing and inspection should follow the provisions described in Section 1703.

Section 1704 Special Inspections and Tests, Contractor Responsibility, and Structural Observations

This section provides administrative requirements for special inspections and tests (1704.2), preparation and submittal of the statement of special inspections (1704.3), the contractor’s statement of responsibility (1704.4), and structural observation by the registered design professional (1704.5). These requirements, along with the provisions for required verification and testing, were reorganized in the 2012 IBC so that requirements for special inspection and testing, the statement of special inspections, contractor’s statement of responsibility, and structural observation are now entirely contained in Section 1704, and all the required inspection and verification requirements are contained in Section 1705. The reorganization of Sections 1704 and 1705 in the 2012 IBC removed several ambiguities and as such is a significant improvement.

One of the oldest mechanisms for providing quality assurance in construction is the process known as special inspection. The purpose of special inspection is to ensure proper fabrication, installation, and placement of components or materials that require special knowledge or expertise, such as welding of structural steel or placement of grouted masonry. The knowledge and duties of a special inspector differ from that of the jurisdiction building inspector in that the special inspector’s expertise is narrower in scope, such as that of a structural steel welding or prestressed concrete special inspector. Another difference is the special inspector is required to be present during certain field operations, whereas the jurisdiction inspector may not be present.

The concept of special inspection dates back to the 1927 edition of the Uniform Building Code (UBC), where it existed under the designation Special Engineering Supervision. The first special inspection provisions similar to those presently used appeared in the 1943 UBC under the designation Registered Inspectors. The requirements in the 1943 UBC contained the following essential elements that are also in the current special inspection provisions:

1. The particular types of work requiring special inspection were specified.

2. The special inspector had to be qualified and demonstrated his or her qualifications to the building official.

3. The requisite special inspections were in addition to those performed by the jurisdiction building inspector.

4. The special inspector was to be employed by the owner or design professional, not the contractor, in order to avoid any conflict of interest.

The special inspection provisions in the 1997 UBC continued with essentially the same elements. Although similar, the special inspection provisions in the IBC were expanded to be much more extensive than those in the UBC.

The special inspection requirements in the IBC address three areas:

1. Adequacy or quality of materials, such as concrete strength

2. Adequacy of fabrication, such as verification of manufacturer’s certified test reports

3. Adequacy of construction techniques, such as proper placement of reinforcing

Special inspection is that category of inspection requiring special knowledge, special attention, or both. The knowledge required is generally more specialized than that required by a general building inspector. An individual with a high degree of specialized knowledge is generally required; hence, the term special inspection.

Most building departments do not have the staff necessary to do detailed inspections on large or complex structures, nor do the permit fees allow the level of inspection necessary for the types of construction where extra care in quality control must be exercised to ensure compliance with the code. In some cases, the special inspection must be continuous during a particular operation, such as pretensioning high-strength bolts or making complete penetration groove welds. Hence, there is a need for a special inspector with specialized expertise who can be there continuously during a particular operation.

ICC offers a publication titled Special Inspection Manual³ that provides the building official with guidance on the administration and implementation of the special inspection requirements of the IBC. The guidance is based on recommended practices and the consensus of building officials and design professionals, as well as inspection and testing agencies. The duties and responsibilities of the building official, special inspector, project owner, engineer or architect of record, contractor, and building official are covered in the guide. Suggested forms are also included that can be easily adapted to the specific needs of the jurisdiction.

Examples of checklist documents for special inspection are included in the Special Inspection Manual (ICC). Copies of this document are available from the ICC.

Another good source of information for special inspection and testing for seismic resistance is the Structural Construction and Special Inspection Manual: A Companion to the 2006 IBC Structural/Seismic Design Manuals developed by the Structural Engineers Association of California (SEAOC). The examples in this manual are based on design examples in the 2006 IBC Structural/Seismic Design Manuals developed by SEAOC.

Note that in addition to the general special inspection requirements in Section 1705, there are additional special inspection requirements in Section 1705.10 that specifically apply to wind resistance, and in Section 1705.11 that specifically apply to seismic resistance.

1704.1 General. This section outlines the general requirements for special inspections, the statement of special inspections, contractor’s statement of responsibility, and structural observations. The actual inspections and verifications required are contained in Section 1705.

1704.2 Special inspections. The owner is responsible for the employment of special inspectors meeting the approval of the building official and all costs associated with the employment of special inspectors. Note that the special inspectors must be employed by the owner, or the responsible registered design professional acting as the owner’s agent, not by the contractor or builder. This ensures independence of the special inspector and avoids any potential conflict of interest that could occur if the special inspector were employed by the contractor or builder. Note that the special inspections required by Chapter 17 are in addition to, not in lieu of, the jurisdiction inspections required by Section 110.

There are exceptions to the requirement for special inspections for minor work or work not required to be designed or sealed by a registered design professional such as Group U occupancies accessory to a residence, and prescriptive cold-formed steel or wood light frame construction. The exemption from special inspection R-3 occupancies was deleted in the 2009 IBC because the structural systems in modern single-family residential buildings can be as complex and challenging as commercial structures, especially large custom homes. Engineered seismic-force-resisting systems are very common in residential structures in Seismic Design Categories D, E, and F. Group R-3 occupancies often have components that require special inspection such as high-load diaphragms, high-strength concrete, structural steel frames, high-strength bolting, complete penetration groove welds, engineered masonry, and deep (pile) foundation systems. The exemption for Group U occupancies accessory to a residential occupancy is for those structures that are typically not required to be designed by a registered design professional or those designed and constructed in accordance with the International Residential Code® (IRC)®. Exception 1 does not necessarily mean that inspections are not required, only that they are not required to be made by a special inspector. However, the above comments regarding structural systems used in the R-3 occupancies could also apply to U occupancies. It is not inconceivable that a large private garage could have structural components that would require special inspection.

Exception 1 refers to “conditions in the jurisdiction” as a possible exception. The primary conditions envisioned by the code in this case refer either to the jurisdiction having the resources and skill level necessary to perform the requisite special inspection tasks, thus obviating the need for a special inspector hired by the owner, or the work is of a minor nature in the opinion of the building official. Note that this exception for special inspection cannot be invoked by the owner. One purpose of the exception is to allow jurisdictions to perform special inspections if the jurisdiction so desires. Exception 3 waives special inspection for prescriptive light-frame construction of cold-formed steel or conventional wood structures. Section 2211.7 applies to prescriptively framed detached one- and two-family dwellings and townhouses less than or equal to three stories constructed of cold-formed steel in accordance with AISI S230.

1704.2.1 Special inspector qualifications. Special inspectors are required to be qualified and demonstrate competence to the satisfaction of the building official. Code changes to the 2009 IBC clarified and expanded the requirements pertaining to special inspector qualifications and also clarified that the registered design professional acting as an approved agency may provide special inspection for work designed by them, provided they demonstrate to the building official that they are qualified to perform the special inspections involved.

1704.2.2 Access for special inspection. Prior to the 2012 IBC, there were no specific requirements for providing access to construction for special inspectors other than the general requirement in Section 110.1. This new section requiring access to the construction specifically applies to special inspection.

1704.2.3 Statement of special inspections. The permit applicant must submit a detailed statement outlining the required special inspections and designate those who will perform the special inspections. In general, the responsible registered design professional is required to prepare the statement of special inspections, because the special inspections relate directly to the design and construction documents required by Sections 107.1 and 1603. The statement of special inspections must conform to the detailed requirements described in Section 1704.3. The exception in Section 1704.2.3 allows the statement of special inspections to be waived for prescriptive light-frame construction of cold-formed steel or conventional wood structures. The exception in Section 1704.3 allows the statement of special inspections to be prepared by a qualified person instead of a registered design professional where approved by the building official for construction that is not designed by or required to be designed by a registered design professional.

Although a statement of special inspections is not required for cold-formed steel structures constructed in accordance with the provisions of Section 2211.7 or conventional wood frame structures constructed in accordance with the prescriptive provisions of Section 2308, it should be noted that Sections 2308.1.1 and 2308.4 permit portions and elements of an otherwise conventional building to be designed in accordance with the engineering provisions of the code; therefore, these engineered elements and portions could require special inspection. For example, an otherwise conventional wood frame residence that uses a steel moment frame to resist lateral forces at the clear story entrance foyer. Such an element is outside of the conventional construction provisions, requires engineering under Section 2308.4, and could require special inspection under Section 1705.2.

1704.2.4 Report requirement. Records of each inspection must be kept and submitted to the building official so as to document compliance with the code. The records must include all inspections made and compliance with the code requirements, as well as all discrepancies or violations. A final report must show that all required special inspections have been made and that discrepancies have been resolved before a certificate of occupancy can be issued by the building official. It is the responsibility of the special inspector to document and submit inspection records to the building official and to the registered design professional in responsible charge. The final special inspection report documenting resolution of discrepancies must be submitted at a time agreed upon by the permit applicant and the building official prior to the commencement of work.

1704.2.5 Special inspection of fabricated items. Unless structural items are fabricated by an approved fabricator as described in the exceptions, special inspection is required during the fabrication process. See Section 1704.2.5.1 regarding fabricator approval requirements.

1704.2.5.1 Fabricator approval. Special inspection at a fabrication plant is not required where a fabricator has been specifically approved by the building official. This approval may be based on available third-party accreditations, previously listed (“approved agency”), or by the building official’s own review of the fabricator’s written procedures and quality assurance/quality control program. The fabricator should be periodically audited by an independent, approved special inspection agency. This section is intended to apply to fabricators accredited by organizations such as International Accreditation Service (IAS), the AISC Certification Program for Structural Steel Fabricators, the Plant Certification Program for steel joists by the Steel Joist Institute, or the Plant Certification Program for precast concrete products by the Precast/Prestressed Concrete Institute. Some premanufactured low-rise metal building manufacturers meet both the AISC Certification Program for Structural Steel Fabricators and the IAS Fabricator Inspection Program and are recognized by most building officials as having the appropriate personnel, organization, experience, knowledge, and equipment to produce the quality required for structural steel buildings.

A minor change to the language of this section was made in the 2009 IBC to avoid a possible misinterpretation. The 2009 IBC states, “Special inspections required by Section 1704 are not required where …” In previous editions of the IBC, the section stated, “Special inspections required by this code are not required where …” The previous language could be interpreted to mean that all special inspections, including that required for seismic and wind resistance, could be waived when work is done by an approved fabricator. Note that special inspections for wind and seismic resistance were not included in Section 1704, but in their own specific Sections 1706 and 1707. With the reorganization of Chapter 17 in the 2012 IBC, the special inspection requirements for wind and seismic resistance are now contained in Section 1705. The implication of this is that all special inspections, including those for wind and seismic resistance, are now waived where fabrication is done in an approved fabricator’s shop as indicated in Section 1704.2.5.

1704.3 Statement of special inspections. There were several code changes to the 2006 IBC that reorganized and clarified the special inspection provisions of Chapter 17 to more clearly convey the intent. Beginning with the 2006 IBC, the term statement of special inspections is used instead of the previous terms, special inspection program and quality assurance plan. Provisions that were formerly covered in the quality assurance plan requirements in the 2003 IBC are now included as part of the statement of special inspections when required by the seismic or wind criteria. In addition, the statement of contractor responsibility requirements were consolidated in the 2006 IBC and put in a separate section, eliminating the redundant language of the 2000 and 2003 IBC, where they appeared in both the wind and seismic quality assurance plans. These code changes, in addition to the changes to the 2009 IBC and the further reorganization in the 2012 and 2015 IBC, make the special inspection provisions in the current edition of the IBC much easier to understand and enforce.

When special inspection, special inspection for wind or seismic resistance, or structural testing and qualification for seismic resistance is required by Section 1705, the registered design professional is required to prepare a detailed statement of special inspections. The statement must be submitted by the permit applicant and is a condition of permit issuance as prescribed in Section 1704.2.3. The statement of special inspection must identify ordinary special inspections required by the various subsections in Section 1705, special inspection requirements for wind resistance prescribed in Section 1705.11, special inspection requirements for seismic resistance prescribed in Section 1705.12, and the seismic testing and certification requirements covered by Section 1713.

In general, the responsible registered design professional is required to prepare the statement of special inspections because the special inspections relate directly to the design and construction documents required by Sections 107.1 and 1603. The exception allows the statement of special inspections to not be prepared by the registered design professional if it is prepared by a qualified person approved by the building official for construction that is not designed by or required to be designed by a registered design professional.

1704.3.1 Content of statement of special inspections. The statement of special inspections must identify the work requiring special inspection or testing. It should include the type and extent of each special inspection or test and indicate whether the inspections are to be continuous or periodic. Where required, the statement also includes the additional special inspection or testing requirements for wind or seismic resistance as prescribed by Sections 1705.11, 1705.12, and 1705.13.

1704.3.2 Seismic requirements in the statement of special inspections. The statement of special inspections must include elements of the seismic-force-resisting system, the designated seismic system and additional systems, components listed in Section 1705.12, and the seismic testing and qualifications required by Section 1705.13. The terms “seismic-force-resisting system” and “designated seismic system” are defined in Section 202.

1704.3.3 Wind requirements in the statement of special inspections. The statement of special inspections must identify the elements of the main wind-force-resisting system and components and cladding (that are subject to special inspection) where the nominal design wind speed, v_asd, meets the criteria specified in Section 1705.11. The nominal design wind speed, v_asd, is a new term introduced into the 2012 IBC as a result of the new ultimate wind speed maps. See discussion under Section 1609 for descriptions of the nominal design wind speed and Exposure Categories.

1704.4 Contractor responsibility. The intent of the section is to require the contractor responsible for construction of the main wind-force-resisting system, the seismic-force-resisting system, the designated seismic system, and those wind-resisting components listed in the statement of special inspections to submit a statement of responsibility to the owner and building official. The statement of responsibility is to be submitted prior to commencement of work on a particular structural system or component, and must acknowledge awareness of special requirements contained in the statement of special inspections. A code change to the 2009 IBC proposed to delete the statement of contractor responsibility requirement entirely. However, this statement of responsibility is considered a central part of a long-standing national effort to improve construction quality for seismic and wind resistance by stressing the contractor’s role in providing adequate quality control during the construction process. The language of the section was simplified and consolidated in the 2009 IBC. In the 2012 IBC, the provision was relocated under Section 1704 along with structural observation. The intent of the statement of responsibility is to ensure that the contractor acknowledges awareness of special requirements contained in the statement of special inspections related to the lateral-force-resisting systems for wind and seismic loads.

1704.5 Submittals to the building official. This is a new section in the 2015 IBC that consolidates and itemizes all the reports and certifications that must be submitted to the building official. Although these various items existed in some form in prior editions of the IBC, they were not all located under one section. Having all these reports and certifications listed in one section helps clarify the requirements.

1704.6 Structural observations. Structural observation requirements first appeared in the 1988 UBC and were applicable to buildings in areas of high seismic risk. The purpose of structural observation is to ensure that critical elements of the lateral-force-resisting system are constructed in general conformance with the design as shown in the approved structural drawings and specifications. Because the registered design professional is most familiar with the design and the details of the lateral-force-resisting system, he or she is the most appropriate person to execute the requisite observations. Note that structural observation is in addition to, not in place of, special inspection, and it does not replace or waive any of the inspections by the jurisdiction inspector required by Section 110.

Structural observation consists of visual observation of specific structural systems by the registered design professional for general conformance with the approved construction documents at significant construction stages and at the completion of the structural system. As noted above, structural observation does not include or waive the inspections performed by the jurisdiction as required by Section 110 or the special inspections required by Section 1705. See the definition of “Structural observation” in Section 202.

Structural observation is triggered by the seismic risk category of the building and the nominal design wind speed at the site. Structural observation is required for buildings assigned to Seismic Design Category D, E, or F when any of the five conditions listed in Section 1704.6.1 exists. Structural observation is also required for buildings where the nominal design wind speed exceeds 110 mph when any of the four conditions listed in Section 1704.6.2 exists.

Prior to performing structural observations, the observer is required to notify the building official in writing of the frequency and extent of structural observations. At the conclusion of work, the structural observer is required to submit a written statement that the site visits have been made and identify any unresolved deficiencies.

It is important to note that the last item in both the code sections (for seismic and wind) allows either the registered design professional or the building official to require structural observation at their discretion.

Section 1705 Required Special Inspections and Tests

In the 2012 IBC, all items requiring special inspection and verification were consolidated in Section 1705. All general administrative requirements related to special inspections, the statement of special inspections, contractor responsibility, and structural observations are contained in Section 1704. Other than the reorganization of Chapter 17 in the 2012 IBC, the most significant change is the deletion of the specific requirements for special inspection of structural steel and masonry structures. In both cases, the code refers to the respective referenced standard for quality assurance requirements related to structural steel and masonry construction.

1705.1.1 Special cases. This section pertaining to special inspection in special cases was relocated from the end to the beginning of the section in the 2012 IBC. Special inspection is required for proposed work that is unique or special or unusual in nature and products or systems that are not specifically addressed in the code or in standards referenced by the code. This section is used to apply special inspection requirements to items that are not specifically covered in the code but are approved under the alternate design and methods of construction provisions in Section 104.11. Many ICC Evaluation Service Reports (ESR) for structural products require special inspection in accordance with this section. For example, ESR 2302 for the Hilti Kwik Bolt 3 requires continuous special inspection during installation.

1705.2 Steel construction. This section sets forth the special inspection requirements for the fabrication and erection of steel structures. Prior editions of the IBC contained detailed requirements for special inspection of structural steel in Table 1704.3. The table contained verification and inspection requirements, whether the inspection is required to be continuous or periodic, the appropriate referenced standard, and the applicable IBC code section. A significant code change to the 2012 IBC by AISC deleted the special inspection requirements for structural steel and replaced them with a reference to the quality assurance and inspection requirements in AISC 360-10.⁵ The special inspection requirements that remain in the code pertain to steel structures other than structural steel, such as cold-formed steel, sheet steel, and reinforcing.

The exception eliminates the need for special inspection of steel structures in certain cases. Special inspection is not required if the fabricator does not alter the properties of the parent material by welding, thermal cutting, or heating operations. For example, if the members being fabricated were cut by mechanical means, such as a band saw, and punched or drilled for bolt holes, with no application of heat, special inspection would not be required. But if the same members were cut with an oxy-acetylene torch, special inspection would be required. Even if special inspection is not required, the fabricator must provide evidence that his tracking procedures are adequate to verify that the material used to fabricate any member meets the required specification, is of the proper grade, and has an associated mill test report.

1705.2.1 Structural steel. As noted above, the section references the quality assurance provisions of AISC 360-10 for special inspection of structural steel. Substantial portions of the special inspection requirements for structural steel were deleted from the 2012 IBC because the 2010 edition of ANSI/AISC 360, Specification for Structural Steel Buildings, incorporates a new Chapter N, which includes comprehensive quality control and quality assurance requirements for structural steel construction. AISC 360, Chapter N, covers quality control requirements pertaining to the structural steel fabricator and erector, as well as quality assurance requirements pertaining to the owner’s inspecting and/or testing agencies. The requirements in ANSI/AISC 360-10 are similar to those that were incorporated into AISC 341-05,⁶ Appendix Q. AISC 360-10, Chapter N, provides the foundation for the quality control and quality assurance requirements for general structural steel construction, along with AISC 341-10, Chapter I, thereby extending specific requirements to high-seismic applications. The inspection requirements in AISC 360-10 of the Quality Assurance Inspector are purported to be equivalent to those specified for the special inspector in IBC Chapter 17.

Section 1704.3 of the 2009 IBC addressed all forms of steel construction, but the majority of the requirements in the section and Table 1704.3 pertained to structural steel construction and therefore were deleted. However, some items apply to cold-formed steel construction and rebar welding, which are not covered by AISC 360. In the 2012 IBC, requirements for special inspection of other forms of steel construction are in a separate section and in a reduced Table 1705.2.2 covering steel construction other than structural steel. This table was deleted in the 2015 IBC because the requirements are contained in SDI QA/QC for steel decks and Table 1705.3 for rebar welding. The exception in Section 1705.2 has been retained but modified to clarify the requirement. In practice, the “representative mill test reports” are supplied as described in the AISC Code of Standard Practice, so the added sentence in the exception on mill test reports allows traceability when required by the construction documents and defers to AISC 360 in other cases.

1705.2.2 Cold-formed steel deck. This is a new section pertaining to special inspection for cold-formed steel decks and coordinates the provisions with new terminology used for structural steel elements in Chapter 22, AISC 360, and the new SDI standard. A new SDI Standard for Quality Control and Quality Assurance for Installation of Steel Deck (SDI QA/QC) is referenced for inspection of steel floor and roof decks. The new SDI QA/QC-2011 standard contains provisions for quality assurance inspection of steel floor and roof deck, which are coordinated with the requirements of AISC 360. The standard clarifies the scope of required inspections and responsibilities of both the installer’s quality control personnel and quality assurance inspector, and contains tables of inspection tasks that specifically list inspection requirements for material verification, deck installation, welding, and mechanical fastening. The tables amplify and clarify the basic special inspection requirements for steel deck that were contained in the 2012 IBC, bringing all special inspection requirements for steel deck into one place. This standard references AWS D1.3 for weld quality and requiring material verification.

1705.2.3 Open-web steel joists and joist girders. This is a new section in the 2015 IBC requiring special inspection during installation of open-web steel joists and joist girders; it also contains new Table 1705.2.3, that specifies the type of inspection, applicable code section, and referenced standard. The structural design and installation of open-web steel joist and joist girder systems warrants special inspection by personnel with sufficient expertise and approval by the building official having the necessary competence to inspect the installation of steel joist systems. Examples of important items that require special inspection are bearing seat attachments, field splices, and bridging attachments. Where steel joist systems are used in roof and floor diaphragms, chords and collectors are important critical elements of the lateral-force-resisting system. Although the standard specifications for open-web steel joists (SJI-K-2010 and SJI-LH/DLH-2010), joist girders (SJI-JG-2010), and composite steel joists (SJI-CJ-2010) by the Steel Joist Institute (SJI) contain provisions for inspections, they are limited to quality control inspections by the manufacturer before shipment to verify compliance and workmanship with the specifications. (Refer to Section 5.12 of SJI-K-2010, Section 104.13 of SJI-LH/DLH-2010, Section 1004.10 of SJI-JG-2010, and Section 104.13 of SJI-CJ-2010.) The SJI standards, SJI CJ, SJI K, SJI LH/DLH, and SJI JG are referenced in Section 2207.1 as shown in the table. Although the sections of the SJI standards noted above are also referenced in Section 4 of the Code of Standard Practice for Steel Joists and Joist Girders (SJI-COSP-2010) and the Code of Standard Practice for Composite Steel Joists (SJI-CJCOSP-2010), these SJI codes of standard practice are not directly referenced in the IBC.

Table 1705.2.3 Required Special Inspections of Open-web Steel Joists and Joist Girders. This new table in the 2015 IBC specifies what items require special inspection, whether continuous or periodic, and gives a reference to the applicable standard listed in Section 2207.1. Note that the inspections are periodic meaning that the special inspector can do the inspection after installation and need not necessarily be present during the operation.

1705.2.4 Cold-formed steel trusses spanning 60 feet or greater. This is a new section that was added to the 2009 IBC requiring special inspection for cold-formed steel trusses spanning more than 60 feet. Because long-span trusses have significant loads and support reactions, proper installation and bracing is of critical importance. The special inspector must verify that the temporary and permanent truss bracings are installed in accordance with the approved truss engineering and submittal package. A similar requirement was added for metal-plate-connected wood trusses in Section 1705.5.2.

1705.3 Concrete construction. This section provides the special inspection and verification requirements for concrete construction such as buildings, foundations, and other elements. Detailed requirements are covered in Table 1705.3, which provides the specific verification and inspection requirements, whether the frequency of inspection is to be continuous or periodic, the applicable referenced standard, and/or the IBC code section where appropriate. Exceptions for special inspection are isolated spread footings for buildings three stories or less in height, lightly loaded elements such as slabs on grade and concrete foundations such as conventional foundations for light-frame construction and nonstructural concrete flatwork such as sidewalks, patios, and driveways. Where certain criteria are met, Exceptions 1 and 2 exempt conventional foundations, either spread (pad) footings or continuous footings, for buildings three stores or less in height. Under Exception 2, Item 2.3 exempts continuous concrete footings from special inspection where the structural design of the footing is based on a specified concrete strength of 2,500 psi, even if a higher specified compressive strength is provided for other reasons such as durability. This allows engineers to specify a higher concrete strength as a matter of preference where a 2,500-psi design strength is otherwise acceptable. Note that Section 1808.8.1 requires a specified concrete strength of 3,000 psi for foundations in Seismic Design Category D, E, or F. This means that foundation concrete in Seismic Design Category D or higher must be designed for a specified concrete strength of 3,000 psi concrete, and therefore special inspection is required. However, Table 1808.8.1 allows a specified concrete strength of 2,500 psi for Group R or U of light-frame construction two stories or less in height for foundations in Seismic Design Category D, E, or F. Therefore, 2,500 psi concrete is permitted for these structures, and special inspection would not be required.

Concrete basement or foundation walls constructed in accordance with the prescriptive provisions in Section 1807.1.6.2 are not required to be engineered and are also exempt from special inspection.

1705.3.1 Material tests. Constituent materials for concrete such as aggregate, cement, admixtures, and water must conform to the requirements set forth in Section 1903 and the standards of Chapter 3 of ACI 318. When sufficient documentation is not available to verify that constituent materials conform to these requirements, the building official should require testing of the materials. It should be noted that the special inspection provisions for reinforcing steel were relocated from Section 1705.2 (Steel construction) to Section 1705.3 (Concrete construction) in the 2015 IBC. Where welded reinforcing does not conform to ASTM A706, the reinforcing must comply with Section 26.5.4 of ACI 318, which requires the material properties to conform to the requirements of AWS D1.4.

Table 1705.3 Required Special Inspections and Tests of Concrete Construction. Table 1705.3 presents the requirements for special inspection of concrete structures in a concise format along with the inspection frequency, applicable referenced standard, and/or code section. The table summarizes the required inspections and test samples necessary to verify that the in-place concrete meets code requirements. Refer to ACI 318² and the applicable ASTM standards for more details on constituent material tests, sampling of fresh concrete, testing of slump or air content, casting of test specimens, and other test requirements.

Item 1—Reinforcement. Inspections of reinforcing should verify that tendons and reinforcement are of the correct size and grade, as required by the approved drawings and specifications, and is properly placed prior to placement of concrete. Proper placement of reinforcement has a significant impact on the integrity and strength of reinforced concrete. The reinforcement should be placed within the tolerances set forth in ACI 318 and ACI 117, Standard Tolerances for Concrete Construction and Materials. Additional requirements of ACI 318, such as surface conditions of reinforcement, spacing limitations, and concrete protection for reinforcement or cover, must also be checked.

Item 2—Welding reinforcement. Item 2, inspection of reinforcing steel welding, refers to AWS D1.4 and ACI 318, for requirements pertaining to welding reinforcing steel.

Item 3—Cast-in-place anchors. Item 3 comes into effect when anchor bolts are cast in concrete. Proper placement and embedment of anchor bolts is of extreme importance. If an anchor bolt is set too low for proper thread engagement, there are few satisfactory methods to remedy the situation. The common practice of placing a puddle weld in the nut is of questionable value, as neither the bolt nor the nut may actually be weldable material. The chemistry of nuts is not controlled by the ASTM requirements, and the chemistry allowed for an ordinary A307 bolt is such that it may or may not be weldable. In either case, the weld is not a prequalified weld in accordance with AWS D1.1, and a Procedure Qualification Record should be developed to qualify the welding procedure. Note also that if the anchor bolt is a high-strength bolt such as an ASTM A325 or ASTM A449, the bolt is quenched and tempered, and application of heat by welding may alter the strength of the bolt and make the bolt brittle.

Two new requirements were added to the 2009 IBC. Item 3 requires continuous special inspection for bolts cast in concrete where the strength design procedure is used, and Item 4 requires periodic special inspection for anchors installed in hardened concrete. For post-installed anchors, the imposition of continuous special inspection was felt to be a hardship for projects involving the installation of large numbers of anchors where simultaneous inspection of all installations is impractical. In the 2012 IBC, Item 3 was changed to require periodic inspection because inspecting cast-in-place anchors is really no different than inspecting placement of reinforcement. Thus, in the 2012 IBC, the anchors in both Items 3 and 4 only require periodic special inspection. The lack of special inspection for bolts designed in accordance with ACI 318-11 Appendix D (which includes all bolts and anchors designed to resist seismic loads) was considered an oversight. Table 1705.3 now requires periodic special inspection for all bolts cast in concrete, continuous special inspection for adhesive anchors installed in horizontally or upwardly inclined orientations designed to resist sustained tension loads, and periodic special inspection for all other mechanical and adhesive anchors. It should be noted that anchoring to concrete is no longer in Appendix D but is now covered in Chapter 17 of ACI 318-14.

Item 4—Post-installed anchors. As noted above, Item 4 requires special inspection for all anchors post-installed in hardened concrete. The 2015 IBC requires continuous special inspection for post-installed adhesive anchors in hardened concrete where the anchors are designed to resist sustained tension loads. All other adhesive and mechanical anchors require periodic special inspection. The new Footnote b was added in the 2012 IBC to account for post-installed anchors approved through the alternate methods of construction provisions of Section 104.11, such as anchors installed in accordance with ICC Evaluation Service Reports. It is also intended to distinguish between the requirements for special inspection of anchors designed to comply with the IBC alone versus those qualified by approved research reports in accordance with ACI 355.2, Qualification of Post-Installed Mechanical Anchors in Concrete. Typically, items requiring special inspection that are approved under Section 104.11 are covered by Section 1705.1.1, Special Cases. Where special inspection requirements are not provided in a research report, the special inspection requirements must be specified by the registered design professional, who would indicate whether inspections are continuous or periodic, and be approved by the building official prior to commencement of the work.

Item 5—Design mix. Item 5 is a particularly important verification on larger projects that may have many required mix designs with differing strength requirements and aggregate sizes.

Item 6—Concrete testing. Sampling of fresh concrete for making specimens for strength tests is extremely important for proper quality control. Properly sampled and prepared specimens are necessary to determine that the concrete will meet or exceed the design strength. The frequency of sampling should be in accordance with ACI 318 Section 26.12.2—one set of specimens for each class of concrete not less than once per day, once per 150 cubic yards, or once per 5,000 square feet of slab or wall. Sampling should be done in accordance with ASTM C 172 to ensure representative samples for determining compressive strength. The tests specified in Item 6 may be supplemented by other tests such as unit weight or air content.

Item 7—Concrete placement. Observation of the actual placement is important to determine that the fresh concrete is properly handled so that it does not segregate during placement and that the concrete is properly consolidated by vibration. The mixing, conveying, and depositing requirements (see ACI 318 Section 26.4.6) should be strictly enforced to ensure proper placement with adequate consolidation and without segregation. Concrete voids or rock pockets can adversely affect design strength and are unattractive.

Item 8—Curing. Maintenance of proper cure is essential to obtaining quality concrete that will reach the design strength. Concrete that is not properly cured often will be below design strength and may suffer degradation at the surface from use or from environmental effects much earlier than properly cured concrete.

Item 9—Prestressed concrete. The inspections required by Item 9 are of extreme importance as the strength of a prestressed member is highly dependent on proper prestressing. When checking the application of prestressing force, both the force applied to the tendon and the tendon elongation should be checked simultaneously to ensure that the tendon has not been hung up in the tendon sheath. See ACI 318 Section 26.9.

Item 10—Precast concrete. Criteria for the erection procedures of precast concrete must be provided on the design drawing by the design engineer. The drawings should identify each panel to be cast and should specify: dimensions and thickness of panels, reinforcement grade, size and location, location of inserts, and minimum concrete strength at lifting and in-service. The special inspector should ensure that the erection process complies with the approved procedures. See ACI 318 Section 26.8.

Item 11—Concrete strength. Concrete strength must be verified prior to stressing tendons used in post-tensioned concrete. Form supports for prestressed concrete should not be removed until sufficient prestressing has been applied. Forms and shoring for conventionally reinforced concrete members such as beams and structural slabs should not be removed until adequate concrete strength is achieved. See ACI 318 Section 26.10.2 for requirements related to removal of formwork.

Item 12—Formwork. Inspection of concrete forms for proper shape, dimensions, and location is essential for adequate performance on concrete members such as beams, columns, walls, and structural slabs. See ACI 318 Section 26.10 for general requirements related to formwork.

1705.4 Masonry construction. The masonry standard is developed by a joint committee of TMS, ACI, and ASCE, called the Masonry Standards Joint Committee (MSJC), and consists of Building Code Requirements for Masonry Structures, TMS 402/ACI 530/ASCE 5,⁷ Specifications for Masonry Structures, TMS 602/ACI 530.1/ASCE 6,⁸ and commentaries to the code and specifications. These documents are often referred to as the MSJC Code and MSJC Specification. Prior to the 2012 edition, the IBC included two tables for verification and inspection of masonry structures. A code change to the 2012 IBC by TMS deleted these special inspection requirements and tables and replaced them with a reference to the quality assurance and inspection requirements in the 2011 edition of the MSJC Code and Specification. The level of quality assurance required by Section 3.1 of the 2013 MSJC Code is driven by the type of masonry used and the risk category of the structure. As previously noted, the term “Occupancy Category” was changed in the 2012 IBC to “Risk Category” to better reflect the meaning. Table 1705-1 reflects the level of quality assurance required based on the type of masonry and risk category of the structure.

There are three exemptions from special inspection for masonry structures. Empirically designed masonry, glass unit masonry, or masonry veneer in Risk Category I, II, or III structures are exempt from special inspection when constructed in accordance with Sections 2109, 2110, or Chapter 14. Note that the MSJC Code requires Level A quality assurance for these structures, which requires no specific testing and only consists of verification of certificates of compliance for masonry materials in accordance with MSJC Specification Article 1.5. The other two exceptions are for masonry foundation walls constructed in accordance with the prescriptive tables of Section 1807.1.6, which do not require engineering, and masonry fireplaces, chimneys, and heaters constructed in accordance with Section 2111, 2112, or 2113.

1705.4.1 Empirically designed masonry, glass unit masonry, and masonry veneer in Risk Category IV. Special inspection for empirically designed masonry, glass unit masonry, and masonry veneer in Risk Category IV structures must comply with TMS 402/ACI 530/ASCE 5 Level B Quality Assurance requirements. See Table 3.1.2 of the 2013 MSJC Code for specific details. As noted, Table 1705-1 shows the level of quality assurance required based on the type of masonry and risk category of the structure.

Table 1705-1. Level of Quality Assurance Required by MSJC Code Section 3.1

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1705.4.2 Vertical masonry foundation elements. The intent of this section is that the special inspection requirements for vertical masonry foundation elements are as noted in Section 1705.4 and its subsections. In other words, vertical masonry foundation elements may be required to comply with quality assurance and inspection provisions of the MSJC Code and Specification, they may be required to only comply with the Level B Quality Assurance requirements prescribed in Section 1705.4.1, or they may be exempt from special inspection in accordance with one of the exceptions. Section 1808.9 references the MSJC Code for design requirements for vertical masonry foundation elements.

1705.5 Wood construction. This section requires special inspection for certain types of wood construction. The requirement is for inspection of prefabricated elements such as wood trusses and refers to Section 1704.2.5 regarding special inspection of fabricators. For portions of wood structures designated as the seismic-force-resisting system, see also the special inspection requirements for wind and seismic resistance discussed in the analysis of Sections 1705.11 and 1705.12. Special inspection is required for site-built assemblies, high-load diaphragms and wood trusses spanning 60 feet or more.

1705.5.1 High-load diaphragms. When lateral loads become significant, designers often use high-load diaphragms, which have multiple rows of fasteners. Proper construction of high-load diaphragms is critical so this section requires periodic special inspection. Design values for high-load diaphragms fastened with nails are in Table 4.2B of the SDPWS, and high-load diaphragms fastened with staples are in Table 2306.2(2). The special inspector is required to inspect the diaphragm for proper sheathing grade and thickness; proper size, species, and grade of framing members; and proper fastener type, size, spacing, and edge distance from sheathing and framing members.

1705.5.2 Metal-plate-connected wood trusses spanning 60 feet or greater. This section requiring special inspection for wood trusses spanning over 60 feet was added to the 2009 IBC. Because long-span trusses have significant loads and support reactions, proper installation and bracing is of critical importance. The special inspector must verify that the temporary and permanent truss bracings are installed in accordance with the approved truss engineering and submittal package. A similar requirement was added for cold-formed steel trusses spanning over 60 feet in Section 1705.2.4.

1705.6 Soils. The table for verification and inspection of soils was added to the 2006 IBC to clarify the specific inspection tasks that are required for soils. Prior to the 2006 IBC, the inspections were presumed to be whatever was required by the geotechnical engineer. This section covers special inspection requirement soils such as site preparation, engineered fills, and materials supporting load-bearing foundations. The load-bearing capacity of the site soil and any fill has a significant impact on the structural integrity of a building supported by the fill. For example, settlements in an improperly compacted fill can cause significant structural distress. Differential settlements of ¼ inch in a 20-foot grade beam can induce stresses that exceed the yield limits. Hence, fills should be engineered and compaction carefully controlled. The special inspection tasks outlined in Table 1705.6 must be performed to verify compliance with the approved construction documents and the geotechnical report required by Section 1803.2. What is required to be included in geotechnical reports is covered in Section 1803.6. The special inspector is required to (1) verify that materials below footings are adequate to achieve the design bearing capacity; (2) verify that excavations are extended to the proper depth and have reached proper bearing material; (3) perform classification and testing of controlled fill materials; (4) verify use of proper materials, densities, and lift thicknesses during placement and compaction of controlled fill material; and (5) verify that the site and subgrade have been properly prepared prior to placement of controlled fill.

The exception in previous editions of the code that exempted placement of controlled fills 12 inches or less in depth from having to comply with the special inspection requirements was changed in the 2009 IBC to require that the special inspector verify a minimum of 90-percent compaction.

1705.7 Driven deep foundations. Special inspection is required for installation and testing of driven deep (pile) foundations. The special inspection tasks outlined in Table 1705.7 are required to verify compliance with the approved construction documents and the geotechnical report required by Section 1803.2. What is required to be included in geotechnical reports is covered in Section 1803.6. The term pile was changed in the 2009 IBC to “driven deep foundation element” to be consistent with changes to Chapter 18. Table 1705.7 requires continuous special inspection to (1) verify that pile materials, sizes, and lengths comply with the requirements; (2) determine capacities of test piles and conduct additional load tests; (3) observe driving operations and maintain complete and accurate records for each pile; and (4) verify placement locations and plumbness, confirm type and size of hammer, record the number of blows per foot of penetration, determine required penetrations to achieve design capacity, record tip and butt elevations, and document any pile damage.

For specialty piles, the special inspector must perform additional inspections in accordance with the registered design professional’s recommendations.

1705.8 Cast-in-place deep foundations. The terminology related to foundations in Chapter 18 was changed in the 2009 IBC. Chapter 18 now has two general types of foundations—shallow foundations and deep foundations. What were previously referred to pier foundations are now covered under the more general category of cast-in-place deep foundations. Continuous special inspection is required for installation and testing of cast-in-place deep foundations. The special inspection tasks outlined in Table 1705.8 are required to verify compliance with the approved foundation and geotechnical report required by Section 1803.2. The table requires the special inspector to observe drilling operations and maintain complete and accurate records for each pile, and verify placement locations and plumbness, and confirm pile diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable), and adequate end-bearing strata capacity. The volume of concrete or grout placed is often the first indicator of potentially significant problems during construction. Item 2 requires the special inspector to record the volumes of concrete or grout placed as a critical diagnostic tool. For concrete cast-in-place deep foundations, Item 3 of the table refers to Table 1705.3 for special inspection tasks related to concrete construction.

Augered piles are drilled and then grouted in place. For each drilled pile, data should include a drilling log showing the types of soils encountered for each foot and the material stratum at the required tip elevation. The inspector should verify that the soil at the required tip elevation is the correct soil. The drilling log should also give information on the duration and cause of any delays, data on the rebar cage and concreting procedures, casing or other procedures necessary to prevent intrusion of ground water, and results of any concrete strength tests.

1705.9 Helical pile foundations. Helical piles are deep foundation systems used for new construction, for foundation repair to mitigate structure settlement, or for tiebacks in shoring applications. Helical piles can be installed with a column of high-strength grout that encases the helical shaft to provide additional compressive and lateral load capacity. The section requires continuous special inspection during installation of helical pile systems. The installation procedure must be in accordance with the recommendations of the registered design professional and the approved geotechnical report.

1705.10 Fabricated items. This new section references Section 1704.2.5 for specific requirements pertaining to special inspection of fabricated items. See further discussion of fabricator approval under Section 1704.2.5.

1705.11 Special inspection for wind resistance. In areas of high seismic risk (i.e., Seismic Design Categories C, D, E, and F), the IBC requires special inspection of seismic-force-resisting systems in buildings of light-frame construction (wood framing and cold-formed steel framing). Similar risks exist in high-wind areas and special inspection of main wind-force-resisting systems and components, and cladding in buildings of light-frame construction is required. Damage to buildings due to high-wind forces often begins with failure of the cladding system, which often exposes the main wind-force-resisting system to damage from wind-driven rain and other forces that the wind-force-resisting system is typically not designed to resist. Unless specifically exempted in the general requirements in Section 1704.2, special inspection for wind resistance is required for buildings sited in Exposure B where the nominal design wind speed is 120 mph or more, and Exposure C or D where the nominal design wind speed is 110 mph or more. The specific requirements apply to structural wood, cold-formed light-frame steel structures, and exterior cladding. The inspections are continuous or periodic depending on the type of structural elements involved. Table 1705-2 summarizes the requirements in Sections 1705.10.1 (wood), 1705.10.2 (cold-formed steel), and 1705.10.3 (cladding).

Table 1705-2. Special Inspection for Wind Resistance

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1705.11.1 Structural wood. Continuous special inspection is required for any field gluing of the main wind-force-resisting system (see Section 202 for definition of main wind-force-resisting system). Periodic special inspection is required for fastening (nailing, bolting, anchoring) of elements of the main wind-force-resisting system such as shear walls, diaphragms, chords, collectors (drag struts), braces, and hold-downs. The exception applies where the fastener spacing of the sheathing is more than 4 inches on center.

1705.11.2 Cold-formed steel light-frame construction. Continuous special inspection is required for any welding of the main wind-force-resisting system. Periodic special inspection is required for fastening (screw attachment, bolting, anchoring) of elements of the main wind-force-resisting system such as shear walls, braces, diaphragms, chords, collectors (drag struts), and hold-downs. The first exception applies when the sheathing is gypsum board or fiberboard because of their relatively low load capacity. Similar to wood framing, the second exception applies where the fastener spacing of the sheathing is more than 4 inches on center.

1705.11.3 Wind-resisting components. Damage to buildings in high-wind events often begins with failure of the cladding system. Thus, periodic special inspection is required for roof and wall cladding.

1705.12 Special inspection for seismic resistance. Unless specifically exempted in the general requirements in Section 1704.2, special inspection for seismic resistance is required in addition to the general special inspection requirements covered in Section 1704. The requirements are triggered by the seismic design category of the building. Special inspection is required for the seismic-force-resisting system, the designated seismic system, and architectural, mechanical, and electrical components depending on the seismic design category. Other items such as storage racks, base isolation systems, and CFS special bolted moment frames require periodic special inspection.

The seismic-force-resisting system consists of those structural elements and systems that provide lateral stability of the structure and are specifically designed to provide resistance to the anticipated seismic forces. The designated seismic system consists of those architectural, electrical, and mechanical systems and components that require design in accordance with Chapter 13 of ASCE 7 for which the component importance factor, I_p, is greater than 1.0, as prescribed in Section 13.1.3 of ASCE 7 (see Section 202). Section 13.1.3 of ASCE 7 lists four classes of components that have a component importance factor of 1.5. These are components required to function after an earthquake including fire-sprinkler systems and egress stairways that are not an integral part of the building structure, components containing or conveying toxic materials, components in Risk Category IV structures that are deemed to be necessary for continued operation of the facility, and components containing or conveying hazardous materials. Refer to Section 13.1.3 of ASCE 7 for complete descriptions of these systems. Egress stairways was added to Item 1 of ACE 7-10 Section 13.1.3, and Table 13.5-1 gives amplification/response factors for egress stairways that are not a part of the building structure.

In addition to the general exceptions in Section 1704.2, there are three specific exceptions where special inspection for seismic resistance is not required: Light-frame structures not over 35 feet in height and in which S_DS does not exceed 0.5; buildings with reinforced masonry or reinforced concrete seismic-force-resisting systems not over 25 feet and in which S_DS does not exceed 0.5; and detached one- or two-family dwellings not exceeding two stories that do not have the horizontal or vertical irregularities listed.

1705.12.1 Structural steel. For special inspection requirements for structural steel, the IBC references the quality assurance requirements of AISC 341. A new exception was added to the 2009 IBC that permits steel structures not detailed for seismic resistance that use an R-factor of 3 or less in Seismic Design Category C to be exempt from special inspection for seismic resistance. The exception does not apply to cantilever column systems due to their limited ductility and lack of redundancy. Table 12.2-1 of ASCE 7 assigns “steel systems not specifically detailed for seismic resistance, excluding cantilever column systems,” a response modification coefficient, R, equal to 3 and limits their use to Seismic Design Category A, B, or C. For these building systems, the seismic response coefficient of 3 reflects their inherent lack of ductility. Thus, these structures are permitted to be designed using only AISC 360 and are not required to be detailed in accordance with the additional provisions of AISC 341. The detailing and connections are the same as typical steel buildings following AISC 360, and no additional special inspection or testing is required beyond that ordinarily applied to typical steel buildings.

1705.12.2 Structural wood. The seismic special inspections required for wood structures are primarily to ensure continuity of load path within the seismic lateral-force-resisting system. The walls must transfer their inertial loads to the diaphragms, which in turn transmit the inertial loads through the lateral-force-resisting system to the foundation. Periodic inspection is allowed except in the case of field gluing operations, which are to be continuous. The section requires periodic special inspection for fastening such as nailing, bolting, and anchoring components of the seismic-force-resisting system, which includes chords, collectors (struts), braces, and hold-downs. Particular care should be given to the nailing of diaphragms and shear walls. Common nails are often specified in the design, but smaller-diameter sinkers or power-driven (gun) nails are often substituted in the field because the smaller-diameter nails have a lower lateral resistance. For example, the lateral resistance of a 0.131-inch-diameter power-driven nail used as a replacement for a 10d common nail in Douglas Fir-Larch is only 76 pounds, whereas the value for the 10d common nail is 90 pounds. Of additional importance is the connection of collectors to shear walls and the proper installation and tightening of hold-down bolts in shear walls. The exemption from special inspection applies where diaphragm and shear panel construction has a fastener spacing of more than 4 inches on center. Where the fastener spacing is greater than 4 inches, there is lower demand and less potential for splitting, and special inspection is not required.

1705.12.3 Cold-formed steel light-frame construction. Similar to wood framing, the seismic special inspections for cold-formed steel structures are to ensure continuity of load path within the seismic lateral-force-resisting system; that is, the walls must transfer their inertial loads to the diaphragms, which in turn transmit the inertial loads through the lateral-force-resisting system to the foundation. The section requires periodic special inspection of welding and fastening such as screw attachment, bolting, and anchoring components of the seismic-force-resisting system including chords, collectors (struts), braces, and hold-downs. Particular care should be given to connections of braces and hold-downs. Wood and cold-formed steel light-frame constructions have similar requirements for their lateral-force-resisting systems. Therefore, the exception for structural wood also applies, with the appropriate adaptation, to cold-formed steel light-frame construction. The 4-inch spacing for wood construction roughly translates to a minimum capacity of 380 plf. Thus, where fastener spacing for wood structural panel sheathing or steel sheets is greater than 4 inches, there is lower demand and special inspection is not required. The exception for gypsum board and fiberboard shear walls is based on the fact that the capacity of these materials is below the demand threshold.

1705.12.4 Designated seismic systems. As noted above, the designated seismic system consists of those architectural, electrical, and mechanical systems and components that require design in accordance with Chapter 13 of ASCE 7 for which the component importance factor, I_p, is greater than 1.0, as prescribed in Section 13.1.3 of ASCE 7 (see Section 202). Section 13.1.3 of ASCE 7 lists four classes of components that have a component importance factor of 1.5. Refer to Section 13.1.3 of ASCE 7 for complete descriptions of these systems. The special inspector must verify that elements of the designated seismic system that require certification according to Section 1705.13.3 are properly labeled and anchored or mounted in accordance with the certificate of compliance. See discussion of Section 1705.13.3.

1705.12.5 Architectural components. Exterior cladding and veneers can be a serious safety hazard if they become detached from the structure during seismic ground motion as well as potentially blocking required exit paths. The code requires periodic special inspection for exterior cladding, nonbearing walls and partitions, and veneer in Seismic Design Category D, E, or F. The exemption from special inspection applies to these elements when they are relatively low or lightweight. Thus, special inspection is not required when these elements are 30 feet or less above grade or the walking surface, are light-weight cladding and veneer weighing 5 psf or less, or light-weight partitions weighing 15 psf or less.

1705.12.5.1 Access floors. Access floors consist of a system of panels and supports that create a raised floor above the actual structural floor system. The space between the raised floor and the structural floor contains components like wiring for power, voice, and data. The space may also be used for HVAC distribution either as a plenum or with ductwork. Because failure of the floor system can pose a threat to the occupants in high seismic areas, periodic special inspection is required for anchorages of access floors in structures in Seismic Design Category D, E, or F.

1705.12.6 Plumbing, Mechanical, and electrical components. Inspection is necessary for components that must function in post-earthquake conditions, such as emergency electrical systems, or for anchorage of mechanical equipment, piping, and ducting using or carrying flammable or hazardous materials. Periodic special inspection is required for the following items in structures in Seismic Design Category C, D, E, or F: (1) during the anchorage of electrical equipment for emergency or standby power systems; (2) during installation of piping systems intended to carry hazardous contents and their associated mechanical units; (3) during the installation of HVAC ductwork that contains hazardous materials; and (4) during installation of vibration isolation systems in structures where the design requires ¼ inch or less between the equipment support frame and restraint. For structures in Seismic Design Category E or F, periodic special inspection is required for the installation of anchorage systems of all other electrical equipment.

1705.12.5.7 Storage racks. Tall storage racks such as those typically found in large “big box” building supply stores can pose a threat to the public in high seismic areas. Because proper anchorage is critical to keep tall storage racks from overturning during a seismic event, periodic special inspection is required for storage racks 8 feet or greater in height in Seismic Design Category D, E, or F.

1705.12.8 Seismic isolation systems. The performance of seismic isolators is critical to the performance of isolation systems and energy dissipation devices. Periodic special inspection is required during fabrication and installation of these devices. See Section 1705.13.4, which refers to Section 17.8 of ASCE 7 for testing of seismic isolation systems.

1705.12.9 Cold-formed steel special bolted moment frames. This is a new section in the 2015 IBC that requires periodic special inspection for cold-formed steel special bolted moment frames (CFS-SBMF) in structures assigned to Seismic Design Category D, E, or F. The CFS-SBMF is a relatively new type of cold-formed steel moment frame seismic-force-resisting system designed to withstand anticipated seismic forces by dissipation of energy through controlled inelastic deformation. The system is listed in Table 12.2-1 of ASCE 7-10 (see Item C.12; R = 3.5, Ω_o = 3.0, C_d = 3.5). Examples of items that warrant special inspection are critical elements of the system such as installation of the beam-to-column connections and the anchorage to the foundation. The Standard for Seismic Design of Cold-Formed Steel Structural Systems—Special Bolted Moment Frames, 2007 Edition with Supplement No. 1 (AISI S110-07/S1-09) contains provisions for inspections and quality control by the fabricator. The AISI S110 standard is used in conjunction with AISI S100-12, North American Specification for the Design of Cold-Formed Steel Structural Members.

1705.13 Testing for seismic resistance. This section was revised entirely and reorganized in the 2015 IBC to facilitate use and clarify the intent. Several items related to concrete construction were relocated under new Section 1704.5, Submittals to the building official, such as material property reports (carbon equivalence) to verify weldability of reinforcing bars other than ASTM A706 and mill test reports for ASTM A615 reinforcing bars used in certain elements of the seismic-force-resisting system in structures in Seismic Design Categories other than A. The specific testing requirements related to seismic resistance are prescribed in Sections 1705.13.1 through 1705.13.4 unless exempted from special inspection by one or more of the exceptions in the more general Section 1704.2.

1705.13.1 Structural steel. Nondestructive testing of structural steel elements in seismic-force-resisting systems, including struts, collectors, chords, and foundation elements of buildings assigned to Seismic Design Category B through F is required in accordance with the quality assurance requirements of AISC 341. Note that the seismic-force-resisting systems of structures assigned to Seismic Design Category B or C with a response modification coefficient of 3 or less that are not specifically detailed for seismic resistance are exempt. The exception does not apply to cantilever column systems due to their response characteristics and limited ductility.

1705.13.2 Nonstructural components. For structures assigned to Seismic Design Category B through F, nonstructural components, supports, and attachments must meet the seismic qualification requirements of Item 2 of Section 13.2.1 of ASCE 7. Item 2 requires submittal of the manufacturer’s certification that the component is qualified by at least one of the following: (a) analysis, (b) testing in accordance with the alternative found in Section 13.2.5, or (c) experience data in accordance with the alternative prescribed in Section 13.2.6. The registered design professional is required to indicate on the construction documents the requirements for seismic qualification and certificates of compliance documenting that qualification requirements are met and must be submitted to the building official as required by Section 1704.5.

1705.13.3 Designated seismic systems. Structures assigned to Seismic Design Categories C through F with designated seismic systems that are subject to the requirements of Section 13.2.2 of ASCE 7 require certification as follows: (1) Active mechanical and electrical equipment that must remain operable following the design earthquake ground motion is to be certified by the manufacturer as operable. Active parts or energized components must be certified on the basis of approved shake table testing in accordance with Section 13.2.5 or experience data in accordance with Section 13.2.6 unless it can be shown that the component is “inherently rugged” by comparison with similar seismically qualified components. (2) Components assigned a component importance factor of 1.5 with hazardous substances must be certified by the manufacturer that they maintain containment following the design earthquake ground motion by (a) analysis, (b) approved shake table testing in accordance with Section 13.2.5, or (c) experience data in accordance with Section 13.2.6. As noted above for the seismic-force-resisting system, the registered design professional is required to indicate on the construction documents the requirements for seismic qualification and certificates of compliance documenting that the qualification requirements are met and must be submitted to the building official as specified in Section 1704.5.

1705.13.4 Seismic isolation systems. Seismic isolation systems in seismically isolated structures assigned to Seismic Design Category B through F must be tested in accordance with Section 17.8 of ASCE 7. ASCE 7 Section 17.8 requires the deformation characteristics and damping values of the isolation system used in the design and analysis be based on tests of a selected sample of the components prior to construction. The isolation system components to be tested are required to include wind-restraint systems where these systems are used in the design.

1705.14 Sprayed fire-resistant materials. This section provides requirements for special inspection of spray applied fire-resistant materials (SFRM) for floor, roof, and wall assemblies, and structural members. For an SFRM to perform as intended, its application must be within the proper range for certain parameters as determined by the system manufacturer. Requirements are provided for physical and visual testing to demonstrate compliance with the required fire-resistance rating and applicable listing, with specific requirements given for structural member surface conditions, proper application, thickness, density and bond strength. These parameters must be checked prior to and during installation of the SFRM.

1705.15 Mastic and intumescent fire-resistant coatings. Where fire-resistant coatings are used on structural members and decks, the special inspector must verify that they are applied in accordance with the Association of the Wall and Ceiling Industry Technical Manual 12-B⁹ (AWCI 12-B), Standard Practice for the Testing and Inspection of Field Applied Thin Film Intumescent Fire-Resistive Materials, based on the required fire resistance as shown in the approved construction documents.

1705.16 Exterior insulation and finish systems (EIFS). Special inspection is required for exterior insulation and finish systems (EIFS) based on the approved research report and manufacturer’s installation instructions. Critical areas necessary for adequate EIFS performance are proper installation of the waterproofing membrane and installation of flashings at windows, doors, joints, eaves, corners, and penetrations. The Association of the Wall and Ceiling Industry (AWCI) offers training and certification programs for performing proper special inspection of EIFS systems. The exceptions from requiring special inspection are for EIFS installed over a water-resistive barrier, or concrete or masonry walls.

1705.16.1 Water-resistant barrier coating. Where a water-resistive barrier coating is applied between the EIFS and the sheathing, special inspection is required for the barrier coating. The coating must be properly applied to provide additional protection to the building from incidental moisture intrusion that may occur through the building envelope.

1705.17 Fire-resistant penetrations and joints. This is a new section that was added to the 2012 IBC requiring special inspection of fire-resistant penetrations and joints in high-rise buildings or buildings in Risk Category III or IV. Through-penetration and membrane-penetration firestop systems, as well as fire-resistant joint systems and perimeter fire barrier systems, are critical to maintaining the fire-resistive integrity of fire-resistance-rated construction elements, including fire walls, fire barriers, fire partitions, smoke barriers, and horizontal assemblies. The proper selection and installation of such systems must be in compliance with the code and/or appropriate listing. Where these systems are used in two categories of buildings considered as “high risk,” they must be included in the special inspection program.

Although the proper application of firestop and joint system requirements is very important in all types and sizes of buildings, the requirement for special inspection is limited to specific building types that represent a substantial hazard to human life in the event of a system failure or that are considered to be essential facilities. Inspection conforming to ASTM E 2174 for penetration firestop systems and ASTM E 2393 for fire-resistant joint systems increases the level of quality assurance.

1705.17.1 Penetration firestops. A primary method of addressing a penetration of a fire-resistance-rated wall assembly is through the use of an approved firestop system installed in accordance with ASTM E 814 or UL 1479. The system must have an F rating that is not less than the fire-resistance rating of the wall being penetrated. It is critical that the firestop system be appropriate for the penetration being protected. The choice of firestop systems varies based on the size and material of the penetrating item, as well as the construction materials and fire-resistance rating of the wall being penetrated. Special inspection of the firestop system is intended to verify that the appropriate system has been specified and the installation is in conformance with its listing.

1705.17.2 Fire-resistant joint systems. A joint is defined as a “linear opening in or between adjacent fire-resistance-rated assemblies that is designed to allow independent movement of the building in any plane caused by thermal, seismic, wind or any other loading.” The joint creates an interruption of the fire-resistant integrity of the wall or floor system, requiring the use of an appropriate fire-resistant joint system. The code mandates general installation criteria for such systems and requires them to be tested in accordance with ASTM E 1966 or UL 2079. Much like the inspection of penetration firestop systems, the proper choice and installation of fire-resistant joint systems can be verified through a comprehensive special inspection process. Although regulated under the provisions for fire-resistant joint systems, a second type of system is technically not a joint, but rather an extension of protection afforded by a horizontal assembly. The void created at the intersection of an exterior curtain wall assembly and a fire-resistance-rated floor or floor-ceiling assembly must be filled in a manner that maintains the integrity of the horizontal assembly. The system utilized to fill the void must be in compliance with ASTM E 2307 and able to resist the passage of flame for a time period equal to that of the floor assembly. Special inspection is necessary to ensure that the appropriate joint system is chosen and properly installed.

1705.18 Testing for smoke control. This section, although related to mechanical systems rather than structural or architectural systems, is required by the code because the mechanical ductwork and signaling devices are likely to be concealed during the building construction, and the ductwork needs to be leakage tested prior to concealment.

1705.18.1 Testing scope. The special inspection applies to leakage testing of the ductwork prior to concealment and overall system performance of the completed system prior to occupancy.

1705.18.2 Qualifications. The special inspection agencies that perform the testing are required to have specific expertise in fire protection or mechanical engineering and air balancing. The Associated Air Balance Council (AABC) is the certifying association for air balance testing. AABC has certifications for technicians and equipment commissioning.

Section 1706 Design Strengths of Materials

This section requires the strength of structural materials to conform to the applicable design standards, or in the absence of such standards, must conform to accepted engineering practice.

1706.2 New materials. Materials not explicitly covered by the code are allowed, subject to testing that demonstrates adequate performance. Section 1707 provides alternative test procedures, and Section 104.11 provides administrative means of accepting alternative methods of design and construction.

Section 1707 Alternate Test Procedures

Test reports from approved agencies may be used as the basis for approval of materials not specifically covered by the code or approved standards. New materials not covered in the code are also mentioned in Section 1701.2. This section references Section 104.11 in regard to the use of new, innovative, or alternative materials. The building official has the authority to accept such materials based on reports from an approved agency that is independent from the material supplier. ICC Evaluation Service Reports are the most straightforward method used by building officials to review products and systems that are not specifically covered by the code. The cost associated with performing testing and issuing research reports is to be borne by the applicant which is the owner or the owner’s agent.

Section 1708 In Situ Load Tests

This section covers structural analysis or load testing for existing structures or portions thereof where the load-bearing capacity or stability is in doubt.

1708.1 General. When there is doubt as to the structural integrity, load-carrying capacity, or stability of an existing structure or portion thereof, the building official has the option of requiring a structural analysis or a load test, or both. If an engineering analysis is required, it should be based on the as-built conditions and actual material properties. If the structural analysis shows that the structure is not capable of safely carrying the code-design loads, the structure must be load tested. If the structure is found to be inadequate or unstable, the structural system must be modified to provide adequate structural integrity.

1708.2 Test standards. When load-test procedures are given in a referenced standard, those procedures should be followed. An example would be the test procedures in the SJI standard specification.¹¹ When the referenced standard lacks a load test procedure or there is no referenced standard for the structure or portions thereof, a registered design professional should develop a test procedure and test protocol that simulate the actual loading conditions and displacements that the structure is expected to sustain.

1708.3 In situ load tests. In situ tests fall into two categories: procedures specified and procedures not specified. Load testing must simulate the loading required by Chapter 16 and be performed under the supervision of the registered design professional.

1708.3.1 Load test procedure specified. When the applicable standard has a test procedure and acceptance criteria specified, the requirements of the standard should be applied.

1708.3.2 Load test procedures not specified. When there is no applicable load test procedure in a referenced standard, the structure or portion thereof should be tested with a loading protocol that simulates the actual loads and deformations, both lateral and vertical, that the structure is expected to receive. For the gravity system, the vertical loads should be equal to the factored design loads. Dead loads should include expected partition loads.

The language of this section was modified in the 2015 IBC to clarify static load test requirements, remove the arbitrary factor of 2, and specify how to test components that carry dynamic loads. The new code language also considers differences influenced by load duration effects when testing wood elements.

Section 1709 Preconstruction Load Tests

This section applies to materials or methods of construction that are not capable of being designed by conventional engineering analysis or do not comply with referenced standards.

1709.1 General. When the load-carrying capacity and the physical properties of materials or methods of construction are not amenable to analysis by accepted engineering methods, or the material or method does not comply with applicable standards, the structural load capacity and physical properties must be determined by tests specified in this section. Where tests meet the requirements of the code and approved procedures, the building official is required to accept certified reports of tests conducted by an approved testing agency. This section is applicable to components, assemblies, and elements of structures, for example, windows. This section is not applicable to load testing of existing structures (see discussion of Section 1708).

1709.2 Load test procedures specified. When an applicable standard has a test procedure and acceptance criteria, the standard should be applied.

1709.3 Load test procedures not specified. When there is no applicable load test procedure in a referenced standard, the structure or portion thereof should be tested with a loading protocol that simulates the applicable loading conditions and deformations, both lateral and vertical, that the structure is expected to sustain. For components, assemblies, and elements that are not part of the seismic-force-resisting system, the loading and acceptance criteria are set forth in Section 1709.3.1.

1709.3.1 Test procedure. The loading procedure and acceptance criteria use commonly accepted engineering practices to test the adequacy of the component or assembly to resist structural failure at the design loads. The test load is 2 times the design load for 24 hours, and must recover at least 75 percent of the maximum deflection within 24 hours after the test. The test assembly is then reloaded until failure occurs or 2½ times the load corresponding to the maximum allowable deflection is reached (see Section 1604.3) or 2½ times the design load is reached. This procedure should be used only for loads for which the upper bounds can be established with a reasonable degree of accuracy such as dead and live loads. This procedure should not be used for earthquake loads and should be used with care for wind loads.

1709.3.2 Deflection. Deflection under design load is limited to the allowable limits set forth in Section 1604.3.

1709.4 Wall and partition assemblies. Walls and partitions must be tested for simultaneous vertical and lateral loads, both with and without door and window framing.

1709.5 Exterior window and door assemblies. Door and window assemblies are generally qualified by the tests specified in Section 1709.5.1, which requires testing and labeling in accordance with the AAMA/WDMA/CSA standard, or tested in accordance with Section 1715.5.2 and the referenced ASTM and DSMA standards. The exception permits allowable wind pressures for smaller units made of identical components, including glass thickness, to be higher as determined by engineering analysis, provided that an additional test is done on the assembly with the highest pressure to validate the analysis. To clarify the intent, the 2015 IBC includes the last sentence requiring the design pressure to be determined using the allowable stress design load combinations of Section 1605.3.

1709.5.1 Exterior windows and doors. Exterior windows and sliding doors must be tested and labeled as conforming to the American Architectural Manufacturers Association/Window and Door Manufacturers Association standard, AAMA/WDMA/CSA101/I.S.2/A440. Side-hinged exterior doors can comply with the standard or meet the requirements of Section 1709.5.2, as discussed below. The products tested and labeled in accordance with the AAMA/WDMA/CSA standard need not comply with the analysis and testing requirements of Section 2403.2 and the deflection limitations specified in Section 2403.3.

1709.5.2 Exterior windows and door assemblies not provided for in Section 1715.5.1. Exterior window and door assemblies not covered by Section 1715.5.1 must be tested in accordance with ASTM E 330. The test load is equal to 1.5 times the design pressure, as determined per Chapter 16, applied for 10 seconds. Exterior window and door assemblies covered by this section and containing glass are required to conform to the requirements of Section 2403. Specific requirements for structural performance of garage doors were added to the 2009 IBC by reference to ASTM E 330 and ANSI/DASMA 108 for sectional garage doors and rolling doors.

1709.6 Skylights and sloped glass. A tubular daylighting device (TDD) is typically field-assembled from a manufactured kit, unlike a unit skylight, which is typically shipped as a factory-assembled unit. The dome of a TDD is not necessarily constructed out of a single panel of glazing material. Thus, separate definition of a TDD was added to Chapter 2 based on the definition in AAMA/WDMA A440, and TDD’s are included in Section 2405.5. The section refers to Chapter 24 for sloped unit skylight and TDD requirements.

1709.7 Test specimens. Test specimens should be representative of what is actually used in practice. Tests must be conducted or witnessed by an independent approved agency.

Overview of Chapter 17

Chapter 17 is designed to improve the construction quality of structural systems through the following requirements:

• Special inspection and testing is required as prescribed in Section 1704. The various types of structural materials, elements, and systems that require verification or testing are listed in Section 1705.

• The registered design professional must provide a detailed statement of special inspections in accordance with Section 1704.3.

• Additional special inspections for wind resistance may be required in accordance with Section 1705.11. The requirements for special inspection for wind resistance are triggered by the nominal design wind speed and exposure category of the building.

• Additional special inspections for seismic resistance may be required in accordance with Section 1705.12. The requirements for special seismic inspection and seismic testing are triggered by the seismic design category of the building.

• Specific structural testing and qualifications for seismic resistance may be required in accordance with Section 1705.13.

• The contractor responsible for constructing the wind or seismic-force-resisting system or component listed in the statement of special inspection must provide a statement of responsibility in accordance with Section 1704.4.

• Structural observation by a registered design professional may be required in accordance with Section 1704.6. The requirements for structural observation are triggered by the seismic design category of the building and the assigned nominal design wind speed.

• Certificates of compliance and mill test reports must be submitted to the building official in accordance with Section 1704.5.

• Special inspection and verification for various types of structural elements and systems prescribed in Section 1705 include steel (Section 1705.2), concrete (Section 1705.3), masonry (Section 1705.4), wood construction (Section 1705.5), soils (Section 1705.6), driven deep foundations (Section 1705.7), cast-in-place deep foundations (Section 1705.8), and helical pile foundations (Section 1705.9). In addition, special inspection is required for special cases such as alternate materials and unusual designs, as prescribed in Section 1705.1.1.

Example Problem

A new fire station building is proposed in Grass Valley, California. The building will be constructed of fully grouted reinforced concrete masonry unit (CMU) walls with a steel truss roof system. What are the specific quality assurance requirements for the masonry construction required by Chapter 17 of the 2015 IBC?

Solution: Because many of the special inspection, structural observation, and structural testing requirements of the IBC are based on the nominal design wind and speed seismic design category, the first step is to determine these parameters for the proposed building. In order to determine the proper wind speed map to use, we first have to determine the risk category of the building.

• Risk category. Table 1604.5 indicates that a fire station is in Risk Category IV.

• Nominal design wind speed. Figure 1609B for Risk Category IV indicates that the ultimate 3-second-gust wind speed for Grass Valley, California, is 115 mph. Using Table 1609.3.1 and interpolating, the nominal design wind speed for the site is 89 mph. Therefore, there are no special requirements in Chapter 17 based on wind speed.

• Seismic Design Category. The latitude and longitude of the building site are determined from the Grass Valley USGS quadrangle map as follows:

Latitude = 39.219 degrees, Longitude = −121.060 degrees.

• From the USGS website program for the 2012 IBC/ASCE 7-10 at http://earthquake.usgs.gov/hazards/designmaps/, the mapped short- and long-period mapped spectral accelerations are:

The mapped spectral acceleration for short periods, S_S = 0.588

The mapped spectral acceleration for 1-second period, S₁ = 0.243

• These mapped spectral acceleration values are for Site Class B soils. Since S₁ is less than 0.75g, the building is not in Seismic Design Category F (see Section 1613.3.5). Assuming Site Class D without a geotechnical report that establishes the site class is permitted under Section 1613.3.2. Because the existing soil at the site is firm, rocky soil, the seismic design category will be determined assuming Site Class D as the default soil profile. From Tables 1613.3.3(1) and 1613.3.3(2), the soil factors F_a and F_v for Site Class D and S_S and S_D are found:

F_a = 1.33

F_v = 1.914

• The design spectral accelerations S_DS and S_D₁ are ⅔ of the soil modified spectral acceleration values as follows:

S_DS = 2/3 (F_a S_S) = 2/3 × 1.33 × 0.588 = 0.521

S_D₁ = 2/3 (F_v S₁) = 2/3 × 1.914 × 0.243 = 0.310

Refer to the 2003 NEHRP Commentary¹² (FEMA 450) for a discussion of the ⅔ factor.

Entering Table 1613.3.5(1) with S_DS = 0.521 and Risk Category IV, we find the building is assigned to Seismic Design Category D. Entering Table 1613.3.5(2) with S_D₁ = 0.310 and Risk Category IV, we find the building is assigned to Seismic Design Category D. The building is therefore assigned to Seismic Design Category D.

Permissible design methods. Section 2109 references Appendix A of the MSJC Code, which specifically prohibits the use of the empirical design method for buildings in Seismic Design Category D, E, or F. Therefore, the proposed fire station building must be designed by the engineering provisions prescribed by either the allowable stress design procedure of Section 2107 or the strength design procedure of Section 2108. The seismic design of the building must conform to Section 2106, which references Chapter 7 of the MSJC Code.

Special inspection. Special inspection is required for all engineered masonry structures. The masonry must be inspected and verified in accordance with the Level C quality assurance requirements of Section 3.13 of TMS 402/ACI 530/ASCE 5 and TMS 602/ACI 530.1/ASCE 6.

Special inspection for seismic resistance. Although the height of the structure does not exceed 25 feet, S_DS exceeds 0.5 seconds so the building does not meet exception 2 of Section 1705.12, and special inspection for seismic resistance is required.

Testing and qualification for seismic resistance. Because the building is in Seismic Design Category D, elements of the seismic-force-resisting system, designated seismic system, and architectural, mechanical, and electrical components must comply with the applicable requirements of Section 1705.13. The designated seismic system consists of those nonstructural components that require design in accordance with Chapter 13 of ASCE 7 with a component importance factor, I_p, greater than 1 in accordance with Section 13.1.3 of ASCE 7. Submittals for reinforcement and structural steel must conform to Section 1704.5.

Contractor responsibility. The contractor responsible for construction of the seismic-force-resisting system and components listed in the statement of special inspections must submit a statement of responsibility to the owner and building official in accordance with Section 1704.4.

Structural observation. Because the building is classified as Risk Category IV and assigned to Seismic Design Category D, Section 1704.6 requires structural observation as defined in Section 202.

Summary of Requirements

• The proposed fire station is in Risk Category IV in accordance with Table 1604.5.

• The seismic design category of the building was determined to be Seismic Design Category D based on assumed Site Class D soil conditions.

• The concrete masonry structural system must be designed in accordance with the engineering provisions prescribed by the allowable stress design procedure of Section 2107 or the strength design procedure of Section 2108.

• As a condition of permit issuance, the registered design professional must provide a statement of special inspections to be submitted by the permit applicant in accordance with Section 1704.3.

• Special inspection must be provided for the masonry construction in accordance with Level C quality assurance requirements of the MSJC Code.

• Special inspection for seismic resistance is required for the seismic-force-resisting system, the designated seismic system, and architectural, mechanical, and electrical components in accordance with Section 1705.12

• The seismic-force-resisting system, the designated seismic system, and architectural, mechanical, and electrical components listed in the statement of special inspections must conform to the testing and qualification for seismic resistance requirements in accordance with Section 1705.13.

• Structural observation for seismic resistance in accordance with Section 1704.5 is required.

• The contractor responsible for construction of the main wind and seismic-force-resisting systems, the designated seismic system, and components listed in the statement of special inspections must submit a statement of responsibility to the owner and building official prior to commencement of work on a particular structural system or component in accordance with Section 1704.4.

KEY POINTS

• Chapter 17 provides requirements for quality assurance for construction of buildings and other structures regulated by the IBC through special inspection and verification, structural testing, and structural observation.

• Specific provisions for approvals, approved agencies, records, labeling, and testing are provided in Section 1703.

• General requirements for special inspections, contractor responsibility, structural observation, fabricator approval, and the statement of special inspections are provided in Section 1704.

• Specific items that require verification by the special inspector are outlined in Section 1705 including special cases, steel, concrete, masonry, wood, soils, and deep foundations.

• Specific verifications are required for wind resistance based on the nominal design wind speed at the site and for seismic resistance based on the seismic design category of the building.

• Special testing and qualification for seismic resistance is required for certain structural elements and architectural, mechanical, and electrical components based on the seismic design category of the building.

• Requirements for alternative test procedures, in situ load testing and preconstruction load testing are provided.

REFERENCES

1. RCSC-04, Specification for Structural Joints Using A325 or A490 Bolts (June 30, 2004), Research Council on Structural Connections, Chicago, IL, 2004.

2. ACI 318-14, Building Code Requirements for Structural Concrete, American Concrete Institute, Farmington Hills, MI, 2014.

3. Special Inspection Manual: 2012 Edition, International Code Council, Washington, DC, 2012.

4. AWS D1.1-04, Structural Welding Code—Steel, American Welding Society, Miami, FL, 2004.

5. AISC 360-10, Specification for Structural Steel Buildings, American Institute for Steel Construction, Inc., Chicago, IL, 2010.

6. AISC 341, Seismic Provisions for Structural Steel Buildings, American Institute of Steel Construction, Chicago, IL, 2010.

7. TMS 402/ACI 530/ASCE 5, Building Code Requirements for Masonry Structures, American Concrete Institute, Farmington Hills, MI, 2013.

8. TMS 602/ACI 530.1/ASCE 6, Specification for Masonry Structures, American Concrete Institute, Farmington Hills, MI, 2013.

9. Technical Manual 12-B, 2nd Edition; Standard Practice for the Testing and Inspection of Field Applied Thin Film Intumescent Fire-Resistive Materials; an Annotated Guide, The Association of the Wall and Ceiling Industries International, Falls Church, VA, 1998.

10. Technical Manual 12-A, 3rd Edition; Standard Practice for the Testing and Inspection of Field Applied Sprayed Fire-Resistive Materials; an Annotated Guide, The Association of Wall and Ceiling Industries International, Falls Church, VA, 2012.

11. SJI, Standard Specification for Joist Girders, Open Web Steel Joists (K-Series), Longspan Steel Joists (LH Series) and Deep Longspan Steel Joists (DLH Series), Steel Joist Institute, Myrtle Beach, SC, 2005.

12. NEHRP, NEHRP (National Earthquake Hazard Reduction Program) Recommended Provisions for New Buildings and Other Structures (FEMA 450), Building Seismic Safety Council, Washington, DC, 2003.

* Items not specifically addressed by the code or a referenced standard can be approved under Section 104.11, Alternative materials, design and methods of construction. ICC Evaluation Services Reports (ICC ESRs) are often used as the basis for approving items that are not specifically addressed by the code or referenced standards.

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