International Code Council 93-Tall-Mass-Timber-Buildings Dumps Questions Answers

ANSI/APA PRG 320 is the governing product standard for performance-rated cross-laminated timber, including adhesive qualification, bond integrity, manufacturing quality control, and required product identification. Accordingly, option D is correct.

Bond-line performance is critical because CLT panels depend on structural adhesive to transfer shear forces between laminations and maintain composite action. PRG 320 establishes qualification and quality-assurance requirements intended to verify that adhesive bonds remain structurally reliable and resist delamination or inadequate bond development. Testing and manufacturing controls under this standard address the completed CLT product rather than treating the adhesive as an isolated material.

AITC 113 concerns dimensional tolerances and related requirements for structural glued-laminated timber rather than CLT bond-line shear qualification. ASTM C557 addresses adhesives for ceramic tile and is unrelated to structural timber manufacture. ANSI 117 is not the governing CLT manufacturing standard.

During inspection, the special inspector ordinarily does not reproduce factory bond-line tests on-site. Instead, the inspector verifies the CLT manufacturer’s identification, certification marks, panel grade, layup designation, and conformance with PRG 320 and the approved construction documents.

References/Topics: 2021 IBC Section 2303.1.4; ANSI/APA PRG 320; CLT adhesive-bond qualification and manufacturing quality assurance.

===============

Option A is the incorrect statement and therefore the required answer. Under 2021 IBC Table 601, an exterior bearing wall in Type IV-C construction requires a two-hour fire-resistance rating , not one hour.

The tall mass timber classifications progressively vary the degree of noncombustible protection and allowable exposure, but the structural fire-resistance requirements remain substantial. Type IV-A exterior bearing walls require three hours. Type IV-B exterior bearing walls require two hours. Type IV-C exterior bearing walls also require two hours. Thus, options B, C, and D correctly reproduce the Table 601 values.

The special inspector must also recognize that Table 601 is not necessarily the only rating criterion affecting an exterior wall. Exterior walls are additionally subject to the requirements associated with fire separation distance, particularly Table 705.5. Where another IBC provision requires a higher rating, that more restrictive condition controls.

For mass timber construction, compliance also depends on the prescribed protective system, member dimensions, connections, joints, intersections, and exterior-side protection. A wall cannot be accepted as compliant solely because the timber cross section appears substantial; it must conform to the approved rated design.

References/Topics: 2021 IBC Section 601; Table 601; Section 602.4; Table 705.5.

===============

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).

===============