93-Tall-Mass-Timber-Buildings International Code Council 93-Tall-Mass-Timber-Buildings Free Practice Exam Questions (2026 Updated)

Option B is correct because the required protection time placed over a mass timber structural connection may be established through a code-recognized fire-resistance evaluation of that protective construction under standard fire exposure.

IBC Section 2304.10.1 regulates connections in Types IV-A, IV-B, and IV-C. The code allows connection fire performance to be demonstrated through testing where the connection is incorporated into the fire-resistance test or through an approved engineering analysis. AWC further clarifies that the protection applied over the connection must provide the necessary protection time and that its performance may be established using the methods recognized by IBC Section 703.3, including testing and engineering analysis based on ASTM E119 or UL 263 performance.

Option A is too narrow: testing an isolated fastener does not establish the fire protection of the entire connection. Options C and D also use the wrong temperature location. Where an engineering-analysis route is used, the temperature criterion applies to the connection itself , including connectors, fasteners, and portions of wood incorporated into the structural connection—not simply to the protected structural element or supported member.

References/Topics: 2021 IBC Section 2304.10.1; Section 703.3; AWC guidance on fire resistance of mass timber connections.

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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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Option D most accurately characterizes Type IV-B under the 2021 IBC. The default rule is that interior faces of mass timber elements—including the inside face of exterior mass timber walls and mass timber roofs—receive noncombustible protection. However, Section 602.4.2.2.2 permits specifically limited portions of walls and ceilings to remain exposed.

That combination of extensive protection plus controlled exposure is the defining practical distinction between Types IV-A, IV-B, and IV-C. Type IV-A requires essentially complete interior protection of mass timber surfaces. Type IV-B uses substantial noncombustible protection but permits limited exposed wall and ceiling areas under quantitative and separation restrictions. Type IV-C, by contrast, permits mass timber interior elements to remain unprotected generally, while retaining special requirements for exterior walls, concealed spaces, and shaft enclosures.

Option A therefore more closely describes the protection philosophy of Type IV-A. Option B invents a 50-percent rule that does not exist in the 2021 IBC. Option C more closely resembles the broad exposure philosophy of Type IV-C, though even that wording oversimplifies its specific requirements.

References/Topics: 2021 IBC Sections 602.4.1, 602.4.2 and 602.4.3; Type IV-A, IV-B and IV-C protection concepts.

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Option C is not an IFC requirement. The 2021 IFC requires inspection records to be maintained on-site, but it does not require those records to be secured in a fire- and water-resistant safe.

Section 3303.2 requires the owner to designate a site safety director. Section 3303.3 then makes that director responsible for completing a daily fire safety inspection of the project site. Every day, building and outdoor construction areas must be evaluated against the prescribed fire-safety inspection items.

The results of each inspection must be documented and retained on-site until a certificate of occupancy has been issued . The records must also be immediately available at the site for presentation to the fire code official upon request. Options A, B, and D therefore accurately reflect the code requirements.

The daily inspection program covers practical hazards such as hot work, temporary heating, combustible debris, temporary electrical wiring, hazardous-material storage, fire apparatus access, hydrants, fire department connections, standpipe availability, and portable extinguishers.

For tall mass timber projects, this documentation is particularly important because substantial combustible construction may be present before permanent fire protection systems are complete.

References/Topics: 2021 IFC Sections 3303.2 and 3303.3; site safety director; daily fire-safety inspection and documentation.

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Yes. The allowance applies to both Type IV-B and Type IV-C construction , making option D correct.

IBC Section 508.4.4.1 regulates the construction of required separations between adjacent occupancies. Where the required separation is formed by a fire barrier or horizontal assembly, mass timber elements are specifically permitted to serve that function in Type IV-B or Type IV-C construction provided the mass timber is separated from the building interior by an approved thermal barrier.

The prescribed thermal barrier is gypsum board not less than 1/2 inch thick , or another material that has been tested and meets both the Temperature Transmission Fire Test and Integrity Fire Test acceptance criteria of NFPA 275.

The requirement is supplemental to the actual fire-resistance rating required for the occupancy separation. In other words, simply installing 1/2-inch gypsum board does not independently create the required fire barrier; the underlying mass timber assembly must also provide the applicable rated performance.

Type IV-HT is not included in this specific Section 508.4.4.1 mass timber allowance.

References/Topics: 2021 IBC Section 508.4.4.1; Type IV-B and IV-C occupancy separations; NFPA 275 thermal barriers.

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The fire resistance of a protected mass timber element is determined by adding the inherent fire resistance of the mass timber to the protection time contributed by the approved noncombustible protection. Therefore, option D is correct.

The mass timber component provides structural endurance through its large cross section and predictable charring behavior. The noncombustible protection delays heating, ignition, and charring of the protected timber surfaces. Its contribution may be established by testing or by assigned values permitted under IBC Section 722.7. The combined value must equal or exceed the rating required for the building element.

Option A ignores the additional protection contribution. Option B ignores the structural endurance provided by the timber after the protective membrane has performed its assigned function. Option C incorrectly substitutes “finish rating time.” A finish rating measures temperature rise behind a protective membrane and is not automatically the same as the added fire-resistance contribution established for protected mass timber.

Inspection must confirm that the protection system matches the approved calculation or tested configuration, including material type, thickness, layer count, fastening, edge treatment, joints, penetrations, and continuity.

References/Topics: 2021 IBC Sections 703.6, 703.8 and 722.7; protected mass timber performance method and noncombustible protection contribution.

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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A proprietary field-glued mass timber beam splice requires special inspection because the connection relies on a field-applied adhesive process that is not covered as a routine prescriptive mass timber connection in Table 1705.5.3. The controlling mechanism is IBC Section 1705.1.1, which authorizes the building official to require special inspection for unusual materials, systems, or installation procedures, particularly where compliance depends on additional manufacturer installation instructions.

The ICC code-development rationale for the tall mass timber provisions specifically identifies field-glued mass timber beam or panel splices as an example of work for which special inspection can be required. Inspection must address the approved evaluation report and manufacturer’s instructions, including substrate preparation, moisture and temperature limits, adhesive storage and expiration, mixing or proportioning, application quantity, open time, member alignment, clamping or pressure, and curing conditions.

Approval by the permit applicant has no regulatory significance. Verification by the registered design professional may supplement the inspection program but does not replace the approved special inspector. A building official may observe the work, but routine field verification by that official is not the prescribed quality-control procedure.

References/Topics: 2021 IBC Sections 1704.2, 1704.3 and 1705.1.1; special cases; proprietary field-glued mass timber splices.

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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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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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Option C correctly states the fundamental UL finish-rating criterion. UL defines a finish rating for assemblies containing combustible wood structural supports as the elapsed fire-exposure time at which the wood member immediately behind the protective membrane reaches the prescribed temperature-rise threshold.

More precisely, UL uses two criteria: an average temperature rise of 250°F or an individual-point temperature rise of 325°F , measured on the plane of the wood nearest the fire, typically between the gypsum membrane and the wood stud or joist. The question asks for the principal definition, which is the 250°F temperature-rise criterion; therefore, option C is correct. Option D incorrectly treats the 325°F individual-point limit as the sole definition.

Options A and B confuse a finish rating with “assigned protection time.” IBC Tables 722.6 and 722.7 provide calculated contribution values for specified protective materials, but those assigned values are not themselves UL finish ratings.

This distinction matters in mass timber fire design because membrane contribution, thermal separation, structural fire resistance, and finish rating are related but not interchangeable concepts.

References/Topics: UL Fire Resistance Directory terminology; finish rating; average 250°F and individual 325°F temperature-rise criteria.

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A separate inspection by the building official is required where the fire resistance of a structural connection in Type IV-A, IV-B, or IV-C construction is provided by wood cover calculated in accordance with Section 2304.10.1. Therefore, option C is correct.

The required inspection occurs after the calculated wood cover has been installed but before additional coverings or finishes conceal the connection. This sequencing allows the building official to verify the actual cover thickness, geometry, continuity, fit, fastening, and correspondence with the approved fire-resistance design.

The requirement is distinct from routine Chapter 17 special inspection. Although a qualified special inspector may observe connection installation and mass timber erection, Section 110.3.5 expressly identifies a required building-department inspection for this calculated wood-cover condition. The inspection cannot be bypassed merely because the connection was observed during structural installation.

A rated joint system under Section 715 is governed by its tested or listed assembly requirements but is not the circumstance identified by this specific inspection provision. The other options do not state the code trigger. Inspectors should therefore coordinate notification before the connection is enclosed because subsequent destructive exposure may otherwise be necessary.

References/Topics: 2021 IBC Sections 110.3.5 and 2304.10.1; inspection of calculated wood cover protecting mass timber connections.

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Adhesive anchors installed horizontally to resist sustained tension loads require continuous special inspection. Therefore, option D is correct.

Continuous special inspection means that the special inspector must be present during the performance of the regulated work. This heightened oversight is necessary because horizontal or upwardly inclined adhesive-anchor installations resisting sustained tension are sensitive to installation variables such as borehole cleaning, adhesive proportioning, mixing, placement, embedment depth, temperature, cure time, and prevention of adhesive loss before curing. A concealed installation defect can substantially reduce long-term tension capacity.

The other listed activities are generally subject to periodic inspection under the mass timber special-inspection provisions. Periodic inspection allows the inspector to observe the work intermittently at appropriate stages rather than remaining present throughout the entire operation. Bolted connections, concealed mass timber connections, and anchorage of mass timber construction to deep foundation systems must still be inspected, but the code does not automatically designate each of those activities as continuous.

The inspector should also verify installer certification where required, approved adhesive-anchor evaluation documentation, expiration dates, storage conditions, drilling method, hole dimensions, and compliance with the approved structural documents.

References/Topics: 2021 IBC Sections 1705.3 and 1705.5.3; Table 1705.3; continuous inspection of adhesive anchors under sustained tension.

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ASTM C920 is the required standard for sealants used under the IBC mass timber air-sealing provision. Option C is therefore correct. Section 703.7 applies to Type IV-A construction and requires compliant sealant or adhesive at specified interfaces involving fire-resistance-rated mass timber elements.

The sealing requirement reduces the movement of air, heat, and combustion gases into gaps that could expose additional timber surfaces and undermine the rated performance assumed by the approved design. The sealant must not merely appear to close the opening; it must be the specified product and installed within its approved joint dimensions and substrate conditions.

ASTM A36 is a structural steel material specification. ASTM E119 establishes procedures for fire testing building construction and assemblies but does not qualify elastomeric sealant products. ASTM F1667 covers driven fasteners such as nails, spikes, and staples and has no application to this sealing requirement.

Under Section 1705.20, installation is subject to periodic special inspection where the Section 703.7 sealant is applied. Inspection should occur before concealment and confirm continuity, adhesion, backing, joint depth, surface cleanliness, and compliance with the approved documents.

References/Topics: 2021 IBC Sections 703.7 and 1705.20; Type IV-A construction; ASTM C920.

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Option D directly reflects the engineering-analysis method authorized by 2021 IBC Section 2304.10.1. For structural connections in Type IV-A, IV-B, or IV-C construction, the analysis must demonstrate that temperatures at every relevant portion of the connection remain within prescribed limits for a period corresponding to the fire-resistance rating required of the connected structural element.

The code establishes two critical temperature-rise limits: an average rise of not more than 250°F and a maximum rise of not more than 325°F . For this purpose, the “connection” includes the connectors, fasteners, and those portions of the wood members that participate structurally in the connection.

Option A is incorrect because ASTM E136 is a test for determining whether a material is noncombustible; it is not the fire-resistance test method for a structural connection. Option B is not a code-recognized substitute for the required connection fire evaluation. Option C is insufficient because a manufacturer’s generalized fire-performance representation does not establish the required code fire-resistance duration unless supported through an approved test, evaluation, or engineering analysis.

References/Topics: 2021 IBC Section 2304.10.1; engineering-analysis method for Type IV-A, IV-B, and IV-C structural connections.

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The illustrated configuration represents Type IV-C construction , so option C is correct. The distinguishing feature is the combination of noncombustible protection on the exterior face with an exposed CLT surface toward the interior.

IBC Section 602.4.3.1 requires the exterior side of combustible exterior walls in Type IV-C construction to have noncombustible protection providing a minimum assigned time of 40 minutes . Table 722.7.1(2) assigns exactly 40 minutes to one layer of 5/8-inch Type X gypsum board, matching the protection illustrated in Figure 66.

The decisive distinction is Section 602.4.3.2: mass timber elements in Type IV-C are permitted to be unprotected on the interior . This is fundamentally different from Type IV-A, where essentially all interior mass timber faces must be protected, and Type IV-B, where interior protection is generally required but limited areas may remain exposed under specific area and separation restrictions.

Type IV-HT does not use the Type IV-C protected-exterior/exposed-interior regulatory scheme.

References/Topics: 2021 IBC Sections 602.4.3, 602.4.3.1 and 602.4.3.2; Table 722.7.1(2), 5/8-inch Type X gypsum board = 40 minutes.

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Type IV-HT construction permits concealed spaces where those spaces comply with the specific protection alternatives prescribed for traditional heavy-timber construction. One permitted method is to completely fill the concealed space with noncombustible insulation. Therefore, option D is correct.

This provision should not be confused with the concealed-space requirements applicable to the tall mass timber classifications—Types IV-A, IV-B, and IV-C. Those classifications employ dedicated noncombustible protection and assigned-time requirements intended to control the contribution of concealed combustible construction during a fire. Type IV-HT follows a different concealed-space framework and allows protection through approved alternatives, including sprinkler protection, gypsum-board enclosure, or complete filling with noncombustible insulation, as applicable.

The insulation must completely occupy the concealed volume. Merely installing partial batt insulation, leaving unprotected voids, or relying on nominally fire-resistant thermal insulation does not satisfy the provision. The inspector should verify the material’s noncombustibility, continuity, placement around obstructions, and conformance with the approved construction documents before the space becomes inaccessible.

References/Topics: 2021 IBC Section 602.4.4; concealed spaces in Type IV-HT construction; noncombustible insulation protection method.

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Option A correctly reflects the required noncombustible protection for protected Type IV-A mass timber. Under IBC Section 602.4.1.2.1, the noncombustible protection applied to interior faces of Type IV-A mass timber must contribute the protection time determined by the applicable provisions of Section 722.7, but not less than 80 minutes .

The broader Type IV provisions are particularly important for interior exit and elevator hoistway enclosures. In qualifying tall mass timber buildings with an occupied floor more than 75 feet above the lowest level of fire department access, mass timber interior exit and elevator hoistway enclosures are permitted up to the specified height limits only where protected in accordance with Section 602.4.1.2. For a two-hour, 120-minute-rated enclosure, at least 80 minutes must therefore come from the prescribed noncombustible protection.

Type IV-B likewise uses an 80-minute minimum for protected interior mass timber, so option B ' s 40-minute value is incorrect. Type IV-C has different exposure allowances and shaft-protection provisions, but option C does not state the controlling tall-building enclosure requirement tested here. Type IV-HT is not governed by the Type IV-A tall mass timber enclosure protection rule.

References/Topics: 2021 IBC Sections 602.4 and 602.4.1.2 through 602.4.1.2.1; Section 722.7.

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Type IV-C generally permits interior mass timber surfaces to remain exposed, but shaft and elevator hoistway enclosures are a specific exception to that broad exposure allowance. Section 602.4.3.6 requires shafts, elevator hoistways, and interior exit stairway enclosures constructed with mass timber to receive noncombustible protection having a minimum assigned protection time of 40 minutes . Option A is therefore correct.

Critically, protection is required on both the inside and outside of the shaft enclosure . The 40-minute value is an assigned contribution from the noncombustible protection; the complete enclosure must still satisfy whatever overall fire-resistance rating is required by Sections 713, 713.4, Table 601, or other applicable provisions.

Option B incorrectly applies the general Type IV-C exposed-interior allowance to a specifically regulated shaft condition. Option C is incomplete because 1/2-inch Type X gypsum board provides only 25 minutes under Table 722.7.1(2), not the required 40 minutes. A 5/8-inch Type X board provides a recognized 40-minute contribution when installed in accordance with Section 722.7.2. Option D does not state the prescribed Type IV-C shaft requirement.

References/Topics: 2021 IBC Sections 602.4.3.2 and 602.4.3.6; Tables 722.7.1(1) and 722.7.1(2).

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