Wash. Admin. Code § 51-11C-40227 - Section C402.2.7-Airspaces

C402.2.7 Airspaces. Where the R-value of an airspace is used for compliance in accordance with Section C401.2, the airspace shall be enclosed in an unventilated cavity constructed to minimize airflow into and out of the enclosed airspace. Airflow shall be deemed minimized where the enclosed airspace is located on the interior side of the continuous air barrier and is bounded on all sides by building components.

EXCEPTION:

The thermal resistance of airspaces located on the exterior side of the continuous air barrier and adjacent to and behind the exterior wall covering material shall be determined in accordance with ASTM C1363 modified with an airflow entering the bottom and exiting the top of the airspace at a minimum air movement rate of not less than 70 mm/sec.

Notes

Wash. Admin. Code § 51-11C-40227

Reserved by WSR 16-03-072, Filed 1/19/2016, effective 7/1/2016 Amended by WSR 19-24-040, Filed 11/26/2019, effective 7/1/2020 Amended by WSR 22-14-091, Filed 7/1/2022, effective 7/1/2023

Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. 13-04-056, § 51-11C-40227, filed 2/1/13, effective 7/1/13.