Statutes, codes, and regulations
Washington Administrative Code
Title 51 - Enterprise Services, Department of (Building Code Council)
Chapter 51-52 - State Building Code adoption and amendment of the 2021 edition of the International Mechanical Code
Section 51-52-0603 - Section 603-Duct construction and installation

Wash. Admin. Code § 51-52-0603

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Current through Register Vol. 24-23, December 1, 2024
Section 51-52-0603 - Section 603-Duct construction and installation

603.5.1 Gypsum ducts. The use of gypsum boards to form air shafts (ducts) shall be limited to return air systems where the air temperatures do not exceed 125ºF (52ºC) and the gypsum board surface temperature is maintained above the airstream dew-point temperature. Supply air ducts formed by gypsum boards shall not be incorporated in air-handling systems utilizing direct evaporative cooling systems.

EXCEPTION:

In other than Group I-2 occupancies, gypsum boards may be used for ducts that are only used for stairwell or elevator pressurization supply air. The gypsum duct shall not attach directly to the equipment.

Wash. Admin. Code § 51-52-0603

Amended by WSR 23-02-055, Filed 1/3/2023, effective 7/1/2023

Statutory Authority: RCW 19.27.190, 19.27.074, 19.27.031 and chapters 19.27 and 34.05 RCW. 10-03-099, § 51-52-0603, filed 1/20/10, effective 7/1/10.