93-Tall-Mass-Timber-Buildings Exam Dumps - International Code Council Special Inspector Questions and Answers

Steel plates are not themselves a fire-protective material for the connection; therefore, option A is the exception. Steel plates frequently form part of mass timber structural connections, but because steel is highly thermally conductive, exposed steel can rapidly transmit heat into fasteners and adjacent wood. Consequently, the steel connection components are normally the items that require protection , not the material relied upon to provide that protection.

AWC guidance recognizes wood cover, fire-rated gypsum board, and other approved protection materials as valid means of shielding structural connections. TR10 specifically provides calculation procedures and worked examples using sacrificial wood cover and Type X gypsum wallboard. An approved protective coating can also be used where its documented fire-performance characteristics establish the required endurance under the approved design.

The distinction is important for inspection. A concealed steel plate does not automatically mean a protected connection. The special inspector must verify whether sufficient wood cover, gypsum protection, approved coating, or another engineered protection system surrounds the steel for the required duration. Hardware geometry, exposed edges, gaps, and penetrations can all materially affect thermal performance.

References/Topics: AWC Technical Report No. 10, protection of structural connections; 2021 IBC Section 2304.10.1; AWC guidance that connection protection can be provided by wood cover, gypsum board, or other approved material.

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Option C is the incorrect statement. The sealing inspection requirements in IBC Section 1705.20 do not automatically apply to every item classified as a “joint” under Section 202. They apply specifically where a sealant or adhesive required by Section 703.7 is installed on mass timber building elements identified in the approved construction documents.

Section 703.7 addresses abutting edges and intersections of fire-resistance-rated mass timber elements and intersections between mass timber and other materials where both elements require a fire-resistance rating. These conditions require periodic special inspection because continuity of the air seal affects the fire performance assumed for the timber assembly.

Option A is correct: qualifying sealants must comply with ASTM C920. Option B is also correct: adhesives used for this purpose must comply with ASTM D3498. Option D reflects the required inspection of sealant applications at the prescribed abutting edges and intersections, although the technically precise term is “mass timber building elements.”

Fire-resistant joint systems are governed separately by IBC Section 715 and may require inspection under Section 1705.18. The two inspection categories must not be treated as interchangeable.

References/Topics: 2021 IBC Sections 703.7, 715, 1705.18 and 1705.20; ASTM C920; ASTM D3498.

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A 7/16-inch wood structural panel does not satisfy the prescribed minimum thickness for fireblocking. Therefore, option C is the exception.

IBC Section 718.2.1 permits one thickness of 23/32-inch wood structural panel where the joints are properly backed. A 7/16-inch panel is substantially thinner and cannot be substituted without an approved alternative-material determination. The code also recognizes one-half-inch gypsum board and properly installed batts or blankets of mineral wool or other approved materials.

Mass timber complying with Section 2304.11 is also permitted as fireblocking. Its large cross section provides resistance to the movement of flame, hot gases, and smoke through a concealed space that is at least equivalent to the nominal lumber traditionally accepted for this purpose.

The inspector must distinguish fireblocking from a tested firestop system. Fireblocking divides or interrupts concealed combustible cavities; it does not automatically protect a penetration through a fire-resistance-rated wall or floor. Installation must completely fill or close the required space, remain securely supported, and comply with requirements for joints, edges, penetrations, and mineral-fiber compression.

References/Topics: 2021 IBC Section 718.2.1; Section 2304.11; approved fireblocking materials in mass timber construction.

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IBC Table 722.7.1(2) assigns a 40-minute protection contribution to 5/8-inch Type X gypsum board . Therefore, option D is correct.

The same table assigns 25 minutes to 1/2-inch Type X gypsum board. Consequently, option B overstates the protection contribution of the thinner Type X panel. Ordinary gypsum board values appearing elsewhere in Section 722 cannot simply be substituted for the specific mass timber noncombustible protection values in Table 722.7.1(2). Options A and C therefore do not state the protection contribution recognized by the mass timber table.

These assigned values are particularly important when multiple layers are required. For example, a two-hour building element requires at least 80 minutes of noncombustible protection under Table 722.7.1(1), which can be satisfied prescriptively with two properly installed layers of 5/8-inch Type X gypsum board, each contributing 40 minutes.

The contribution is valid only when the gypsum board is installed and fastened in accordance with Section 722.7.2.

References/Topics: 2021 IBC Tables 722.7.1(1) and 722.7.1(2); Section 722.7.2; Type X gypsum noncombustible protection.

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The 2021 IBC definition of cross-laminated timber describes a prefabricated engineered wood product consisting of not less than three layers of solid-sawn lumber or structural composite lumber. The adjacent layers are cross oriented and bonded with structural adhesive to form a solid wood element. Accordingly, option C is correct.

Cross orientation means that the principal grain direction of one layer is arranged approximately perpendicular to that of the adjoining layer. This configuration distinguishes CLT from products in which all laminations run parallel, such as conventional glued-laminated timber. The cross-oriented layup provides two-way panel behavior, dimensional stability, and structural capacity in both principal directions.

Option A is incorrect because CLT must contain at least three layers. Option B describes a mechanically laminated product rather than structural glued CLT; nail-laminated timber uses mechanical fasteners, whereas code-compliant CLT uses structural adhesives and must conform to the applicable manufacturing standard. Option D eliminates the defining cross-lamination characteristic and would instead describe a parallel-laminated product.

During inspection, the product label and certification documentation should be checked to confirm the panel was manufactured under the required quality-assurance program.

References/Topics: 2021 IBC Chapter 2 definition of “Cross-Laminated Timber”; Sections 602.4 and 2303.1.4; ANSI/APA PRG 320.

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IBC Table 601 requires floor construction and associated secondary structural members in Types IV-A, IV-B, and IV-C construction to have a two-hour fire-resistance rating. Therefore, option B is correct.

This requirement applies to the complete floor assembly, not only the timber panel. The required two-hour performance may be established through the calculated fire resistance of the mass timber, the contribution of approved noncombustible protection, or a permitted combination of both. Any topping, protective membrane, connection protection, and edge condition that forms part of the approved rated design must be installed accordingly.

The ratings for other building elements should not be transferred to the floor. A three-hour rating applies to the primary structural frame and bearing walls of Type IV-A, but its floor construction remains two hours. Type IV-B and Type IV-C floors also require two hours, even though those construction types permit different degrees of exposed mass timber.

The special inspector must verify panel dimensions, approved layup, protection layers, joints, penetrations, connections, topping thickness, and other details that influence the floor’s rated performance.

References/Topics: 2021 IBC Sections 601 and 602.4; Table 601, floor construction and associated secondary structural members.

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The intended answer is ANSI/AWC NDS Chapter 16. The video option uses “AWS,” but the correct standards organization is the American Wood Council—AWC . Option D is therefore correct based on its intended reference.

IBC Section 722.1 expressly permits exposed wood members and wood decking to have their calculated fire resistance determined in accordance with Chapter 16 of the ANSI/AWC National Design Specification for Wood Construction. The method evaluates charring, the effective char depth, the reduced residual cross section, elevated-temperature effects, loading, and the remaining structural capacity for the required exposure period.

ACI 216.1 applies to concrete and masonry fire resistance. TMS 0216 addresses masonry assemblies. ASCE 29 Chapter 5 provides procedures for calculating the fire resistance of structural steel assemblies. Those references are code-recognized methods, but they apply to different construction materials.

For mass timber inspection, the approved calculations should identify the exposed surfaces, required rating, timber species or product, member dimensions, design loads, protective contribution, and connection treatment. Field reductions in member dimensions can invalidate the calculated fire resistance.

References/Topics: 2021 IBC Section 722.1; ANSI/AWC NDS Chapter 16; calculated fire resistance of exposed wood members and decking.

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Minimum prescriptive dimensions are not themselves a component added into a calculated fire-resistance time. Therefore, option A is the exception.

IBC Section 602.4 states that a mass timber element’s required fire resistance can be based on the fire-resistance contribution of the mass timber, the noncombustible protection, or a combination of those two components. Options B, C, and D reflect those permitted approaches.

Minimum dimensions under Section 2304.11 serve a different function. They establish the minimum cross-sectional size and construction characteristics required for qualifying heavy timber or mass timber elements. A member can satisfy the minimum dimensional requirement without automatically achieving every required one-, two-, or three-hour fire-resistance rating. The structural fire calculation must evaluate the remaining effective section after charring, elevated-temperature effects, applied loading, and any credited protective materials.

The inspector must therefore verify both requirements independently: the installed member must meet the minimum code dimensions and must match the approved fire-resistance design. Increasing a member to the minimum prescriptive size does not by itself replace the required calculation, tested assembly, or approved protection system.

References/Topics: 2021 IBC Sections 602.4, 703.2, 722.7 and 2304.11; calculated mass timber fire resistance.

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The requirement applies to Type IV-C construction. Under the 2021 IBC provisions governing Type IV-C, combustible construction forming concealed spaces must be protected with noncombustible protection having an assigned protection time of not less than 40 minutes. Therefore, option C is correct.

The assigned protection time is determined using the protection-time values prescribed by the code, including the applicable values for gypsum board and other approved noncombustible materials. The provision is intended to delay ignition and involvement of combustible mass timber surfaces located within concealed spaces, where fire growth might otherwise remain undetected and become difficult for fire-suppression personnel to access.

Type IV-A and Type IV-B are subject to more extensive noncombustible protection requirements because those construction types support taller buildings and require greater protection of mass timber elements. Type IV-HT uses the traditional heavy-timber concealed-space provisions and may employ alternative methods, such as complete filling with noncombustible insulation.

During inspection, the special inspector must confirm that the installed layers, thicknesses, fastening patterns, joints, penetrations, and transitions collectively provide the required 40-minute assigned protection time.

References/Topics: 2021 IBC Section 602.4.3.5; Table 722.7.1(1); Type IV-C concealed-space protection.

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A sealant required to resist air passage between qualifying mass timber elements must comply with ASTM C920. Therefore, option C is correct. ASTM C920 is the recognized specification for elastomeric joint sealants and establishes requirements for properties such as movement capability, adhesion, cohesion, hardness, weathering, and durability.

IBC Section 703.7 differentiates between the two materials: sealants must meet ASTM C920, while adhesives must meet ASTM D3498. Option D therefore applies to an adhesive rather than a sealant. ASTM E119 is the standard fire test used to establish the fire-resistance rating of structural members and assemblies; it does not serve as the product specification for the sealant. ASTM E114 is not the applicable standard under this provision.

The stated exception is important. Section 703.7 does not require an additional sealant or adhesive where it is not a required component of the tested fire-resistance-rated assembly. Where the approved assembly or code provision does require it, however, the specified product, location, joint preparation, backing material, depth, width, and tooling must match the approved construction documents.

References/Topics: 2021 IBC Section 703.7; ASTM C920 sealants; ASTM D3498 adhesives; tested fire-resistance-rated assemblies.

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