93-Tall-Mass-Timber-Buildings Exam Dumps - 93-Tall-Mass-Timber-Buildings

Prefabricated wood I-joists are engineered wood framing products, but they are not mass timber elements because their configuration does not meet the minimum solid cross-sectional dimensions required for Type IV mass timber construction. Option B is therefore correct.

An I-joist consists of relatively thin flanges connected by a thin structural web. Its efficient open- web-like cross section is fundamentally different from a large solid, laminated, built-up or panelized timber element. I-joists are separately regulated by IBC Section 2303.1.2 and are manufactured and evaluated in accordance with ASTM D5055.

Solid-sawn lumber can qualify as mass timber when it satisfies the minimum heavy-timber dimensions. Structural glued-laminated timber is a recognized large-section engineered timber product, while cross-laminated timber is explicitly recognized as a panelized mass timber product and is regulated by ANSI/APA PRG 320.

The critical inspection point is that the term “engineered wood” does not automatically mean “mass timber.” The special inspector must verify the product category, minimum dimensions, approved construction type, applicable product standard, identification marks and installation requirements shown in the approved construction documents.

References/Topics: 2021 IBC Chapter 2 definition of “Mass Timber”; Sections 2303.1.2, 2303.1.3, 2303.1.4 and 2304.11; ASTM D5055.

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Section 602.4.2.2.2 permits unprotected mass timber ceilings in Type IV-B construction to equal no more than 20 percent of the floor area , and the code expressly states that attached beams are included when determining that exposed ceiling area.

The floor area is 900 square feet:

20% × 900 = 180 sq. ft. maximum exposed area .

The exposed 12-inch × 18-inch beam extends across the 30-foot room. Its three exposed surfaces consist of the 12-inch-wide bottom and two 18-inch-deep sides:

30 ft × (1 ft + 1.5 ft + 1.5 ft) = 120 sq. ft.

Because the attached beam counts against the ceiling exposure allowance, only:

180 − 120 = 60 sq. ft.

remains available for the exposed ceiling itself.

The exposed ceiling extends across the 30-foot room width, so:

30 ft × X = 60 sq. ft.

Therefore:

X = 2 ft .

Option A is correct. Ignoring the beam surfaces would overstate the permitted ceiling exposure and would contradict the explicit IBC requirement that attached beams be included in the exposed ceiling calculation.

References/Topics: 2021 IBC Section 602.4.2.2.2, Exception 1.1; Type IV-B exposed ceiling and attached-beam area calculations.

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Option A is an exact requirement of the 2021 International Fire Code Section 3303.5 . For Type IV-A, IV-B, and IV-C buildings designed to exceed six stories above grade plane, standpipes must be provided in accordance with IFC Section 3313, unless otherwise approved by the fire code official.

The IFC also requires a water supply for fire department operations, but that supply must be approved by the fire code official and fire chief; the code does not specifically mandate that it be a “portable” water supply. Option B is therefore incorrect.

The remaining options alter important numerical requirements. Where noncombustible protection is required and construction exceeds six stories, at least one layer , not two, must be installed on applicable building elements more than four levels below active mass timber construction before additional floor levels are erected. Required exterior wall coverings are likewise required more than four levels below active mass timber construction, rather than two.

These safeguards reduce the amount of exposed combustible construction while ensuring that effective fire department infrastructure progresses with the building.

References/Topics: 2021 IFC Section 3303.5; Sections 3313 and related construction-stage fire protection requirements.

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Option A reproduces one of the two permitted exterior gypsum-board fastening methods in 2021 IBC Section 722.7.2.2. Type X gypsum board used as noncombustible protection on the exterior side of mass timber walls may be attached using galvanized nails of minimum 12 gage with a 7/16-inch head and sufficient length to penetrate the mass timber at least 1 inch .

The code also permits ASTM C1002 Type S, W, or G screws, but those screws must likewise penetrate the mass timber a minimum of 1 inch . Options C and D are therefore incorrect because they specify only 3/4-inch and 7/8-inch penetration, respectively. Option B is incorrect because it substitutes 16-gage nails for the minimum 12-gage requirement.

Section 722.7.2.2 additionally requires exterior Type X gypsum-board layers to be fastened 12 inches on center each way and 6 inches on center at joints or ends. Panel-edge fasteners must be located at least 1 inch and not more than 2 inches from the edge.

These fastening details are part of the conditions necessary to claim the protection contribution in Table 722.7.1(2).

References/Topics: 2021 IBC Sections 722.7.1 and 722.7.2.2; exterior Type X gypsum-board protection.

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The illustrated wall corresponds to Type IV-A construction , making option A correct. The key indicator is the extensive Type X gypsum protection provided on the interior face of the CLT wall. Figure 63 shows multiple layers of 5/8-inch Type X gypsum board protecting the interior mass timber, together with the required exterior-side protection.

Type IV-A is the most comprehensively protected of the three tall mass timber construction classifications. IBC Section 602.4.1.2 requires the interior faces of all mass timber elements , including the inside face of exterior mass timber walls, to be protected with qualifying noncombustible material. Section 602.4.1.2.1 requires the protection contribution to satisfy Table 722.7.1(1) and never be less than 80 minutes. Type IV-A exterior walls also require at least 40 minutes of noncombustible protection on the outside face.

The three interior layers shown are consistent with a heavily protected Type IV-A rated wall. By contrast, Type IV-B permits limited exposed interior mass timber, while Type IV-C expressly permits mass timber interior elements to remain unprotected. Type IV-HT operates under fundamentally different heavy-timber provisions.

References/Topics: 2021 IBC Sections 602.4.1.1, 602.4.1.2 and 602.4.1.2.1; Tables 601 and 722.7.1(1)-(2).

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IBC Section 703.7 requires sealant or adhesive to resist air passage at the abutting edges and intersections of mass timber building elements where those elements are required to be fire-resistance rated. Section 1705.20 then requires periodic special inspection where those prescribed sealants or adhesives are installed. Option C repeats that first required location accurately.

Option D is defective because the code requires sealing at an intersection between mass timber and another material only where both intersecting building elements are required to be fire-resistance rated. The phrase “one or the other” materially weakens the condition. Option A is also too broad. A code-defined joint is not automatically subject to Section 703.7; fire-resistant joint systems are separately regulated by Section 715 and, where applicable, Section 1705.18.

Option B describes the exception in reverse. Sealant or adhesive need not be added under Section 703.7 where it is not a required component of the tested fire-resistance-rated assembly. When it is part of the listed or tested assembly, it must be installed accordingly, but that statement does not identify the primary location requested.

References/Topics: 2021 IBC Sections 703.7 and 1705.20; sealing of adjacent rated mass timber elements; periodic inspection.

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The required minimum fire flow is 500 gallons per minute , making option C correct.

2021 IFC Section 3313.1 requires an approved temporary or permanent water supply for fire protection to become available at specified stages of construction, including when combustible building materials arrive on the site. Section 3313.2 then establishes the specific requirement: when combustible building materials for the building under construction are delivered, a minimum fire flow of 500 gpm must be provided.

The hydrant supplying this flow must be located within 500 feet of the combustible building materials as measured along an approved fire apparatus access lane. If a single hydrant cannot provide the required coverage because of site configuration, additional hydrants are required.

The 500-gpm value in this question is the construction-stage minimum associated with combustible-material delivery. It should not be mistaken for the final required fire flow of the completed building. Depending on construction type, fire separation distance, building area, and subsequent phases of vertical construction, the required available water supply can be greater.

For mass timber projects, verifying this water supply before large timber packages arrive is a critical construction-phase fire-safety control.

References/Topics: 2021 IFC Sections 3313.1 and 3313.2; combustible building materials; minimum construction fire flow.

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The required minimum fire-resistance rating is two hours , making option C correct. Table 601 assigns a two-hour fire-resistance rating to the primary structural frame in Type IV-C construction. The structural connection between members of that rated frame cannot become a premature failure point in the load path.

IBC Section 2304.10.1 specifically addresses structural connections in Types IV-A, IV-B, and IV-C mass timber construction. Connection protection must provide the fire-resistance performance required for the connected building element. This can be accomplished through protected connection configurations, approved fire testing, or engineering analysis satisfying the applicable code criteria.

The connection includes more than the visible steel plate or bolt. Fasteners, connectors, concealed steel, bearing zones, and portions of the timber participating structurally in the connection must collectively maintain the required performance. A one-hour or 1½-hour connection would undermine a structural frame required to remain functional for two hours. Three hours is the primary-frame rating associated with Type IV-A, not the Type IV-C condition specified here.

The inspector should verify protection thickness, wood cover, gypsum layers, hardware embedment, edge conditions, and approved connection geometry before concealment.

References/Topics: 2021 IBC Table 601; Section 2304.10.1; fire-resistant structural connections in Types IV-A, IV-B, and IV-C.

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