Periodic special inspection of sealants or adhesives shall be conducted where sealants or adhesives are...

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.

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