(Effective until July 1, 2023)

PDFWAC 51-50-0718

Section 718—Concealed spaces.

718.2.1 Fireblocking materials.Fireblocking shall consist of the following materials:
1. Two inch (51 mm) nominal lumber.
2. Two thicknesses of 1 inch (25 mm) nominal lumber with broken lap joints.
3. One thickness of 0.719 inch (18.3 mm) wood structural panels with joints backed by 0.719 inch (18.3 mm) wood structural panels.
4. One thickness of 0.75 inch (19.1 mm) particleboard with joints backed by 0.75 inch (19 mm) particleboard.
5. One half inch (12.7 mm) gypsum board.
6. One fourth inch (6.4 mm) cement-based millboard.
7. Batts or blankets of mineral wool, mineral fiber or other approved materials installed in such a manner as to be securely retained in place.
8. Cellulose insulation installed as tested for the specific application.
9. Mass timber complying with Section 2304.11.
[Statutory Authority: RCW 19.27.031 and 19.27.074. WSR 19-02-038, § 51-50-0718, filed 12/26/18, effective 7/1/19.]
(Effective July 1, 2023)

PDFWAC 51-50-0718

Reserved.

[Statutory Authority: RCW 19.27.031 and 19.27.074. WSR 22-13-094, § 51-50-0718, filed 6/14/22, effective 7/1/23; WSR 19-02-038, § 51-50-0718, filed 12/26/18, effective 7/1/19.]