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(Effective until July 1, 2020)

PDFWAC 51-51-0327

Section R327—Protection against radon.

R327.1 Protection Against Radon. The radon control provisions of Appendix F of this code shall apply to buildings constructed in High Radon Potential Counties (zone 1) designated in Table AF101 (1). The radon control provisions of Appendix F of this code shall also apply to all buildings constructed using the provisions of Section R408.3 Unvented crawl space compliance method.
[Statutory Authority: RCW 19.27.074, 19.27.020, and chapters 19.27 and 34.05 RCW. WSR 07-01-090, § 51-51-0327, filed 12/19/06, effective 7/1/07.]
(Effective July 1, 2020)

PDFWAC 51-51-0327

Section R327Sleeping lofts.

R327.1 General.Sleeping lofts shall comply with Sections R327 through R327.5.
R327.2 Sleeping loft area and dimensions.Sleeping lofts shall meet the minimum area and dimension requirements of Sections R327.2.1 through R327.2.3.
R327.2.1 Area.Sleeping lofts shall have a floor area of not less than 35 square feet (3.25 m2) and less than 70 square feet (6.5 m2).
R327.2.2 Minimum horizontal dimensions.Sleeping lofts shall be not less than 5 feet (1524 mm) in any horizontal dimension.
R327.2.3 Height effect on sleeping loft area. Portions of a sleeping loft with a sloped ceiling measuring less than 3 feet (914 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the loft but shall contribute to the maximum allowable area.
EXCEPTION:
Under gable roofs with a minimum slope of 6 units vertical in 12 units horizontal (50 percent slope), portions of a sleeping loft with a sloped ceiling measuring less than 16 inches (406 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the sleeping loft but shall contribute to the maximum allowable area.
R327.3 Sleeping loft access and egress. The access to and primary egress from sleeping lofts shall be of any type described in Sections R327.3.1 through R327.3.5 and shall meet the sleeping loft where the sleeping loft's ceiling height is not less than 3 feet (914 mm) along the entire width of the access and egress component.
R327.3.1 Stairways. Stairways accessing sleeping lofts shall comply with Sections R327.3.1.1 through R327.3.1.7.
R327.3.1.1 Headroom. The headroom above the sleeping loft access and egress shall be not less than 6 feet 2 inches (1880 mm), as measured vertically, from a sloped line connecting the tread, landing, or landing platform nosing's in the center of their width, and vertically from the landing or landing platform along the center of its width.
R327.3.1.2 Width. Stairways accessing a sleeping loft shall not be less than 17 inches (432 mm) in clear width at or above the handrail. The width below the handrail shall be not less than 20 inches (508 mm).
R327.3.1.3 Treads and risers. Risers for stairs accessing a sleeping loft shall be not less than 7 inches (178 mm) and not more than 12 inches (305 mm) in height. Tread depth and riser height shall be calculated in accordance with one of the following formulas:
1. Under gable roofs with a minimum slope of 6 units vertical in 12 units horizontal (50 percent slope), portions of a sleeping loft with a sloped ceiling measuring less than 16 inches (406 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the sleeping loft but shall contribute to the maximum allowable area.
2. The tread depth shall be 20 inches (508 mm) minus four-thirds of the riser height.
R327.3.1.4 Landings. Intermediate landings and landings at the bottom of stairways shall comply with Section R311.7.6, except that the depth in the direction of travel shall be not less than 24 inches (508 mm).
R327.3.1.5 Landing platforms. The top tread and riser of stairways accessing sleeping lofts shall be constructed as a landing platform where the loft ceiling height is less than 6 feet 2 inches (1880 mm) where the stairway meets the sleeping loft. The landing platform shall be not less than 18 inches (508 mm) in width and in depth measured horizontally from and perpendicular to the nosing of the landing platform. The landing platform riser height to the edge of the sleeping loft floor, shall not be greater than 18 inches (406 to 457 mm) in height.
R327.3.1.6 Handrails. Handrails shall comply with Section R311.7.8.
R327.3.1.7 Stairway guards. Guards at open sides of stairways, landings, and landing platforms shall comply with Section R312.1.
R327.3.2 Ladders. Ladders accessing sleeping lofts shall comply with Sections R326.3.2.1 and R326.3.2.2.
R327.3.2.1 Size and capacity. Ladders accessing sleeping lofts shall have a rung width of not less than 12 inches (305 mm), and 10 inch (254 mm) to 14 inch (356 mm) spacing between rungs. Ladders shall be capable of supporting a 300 pound (136 kg) load on any rung. Rung spacing shall be uniform within 3/8 inch (9.5 mm).
R327.3.2.2 Incline. Ladders shall be installed at 70 to 80 degrees from horizontal.
R327.3.3 Alternating tread devices. Alternating tread devices accessing sleeping lofts shall comply with Sections R311.7.11.1 and R311.7.11.2. The clear width at and below the handrails shall be not less than 20 inches (508 mm).
R327.3.4 Ships ladders. Ships ladders accessing sleeping lofts shall comply with Sections R311.7.12.1 and R311.7.12.2. The clear width at and below handrails shall be not less than 20 inches (508 mm).
R327.4 Sleeping loft guards.Sleeping loft guards shall be located along the open side(s) of sleeping lofts. Sleeping loft guards shall be not less than 36 inches (914 mm) in height or one-half of the clear height to the ceiling, whichever is less. Sleeping loft guards shall comply with Section R312.1.3 and Table R301.5 for their components.
R327.5 Emergency escape and rescue openings. An egress roof access window shall be installed in each sleeping loft and shall be deemed to meet the requirements of Section R310 where installed such that the bottom of the opening is not more than 44 inches (1118 mm) above the sleeping loft floor, provided the egress roof access window complies with the minimum opening area requirements of Section R310.2.1.
[Statutory Authority: RCW 19.27.031 and 19.27.074. WSR 20-03-023, § 51-51-0327, filed 1/6/20, effective 7/1/20. Statutory Authority: RCW 19.27.074, 19.27.020, and chapters 19.27 and 34.05 RCW. WSR 07-01-090, § 51-51-0327, filed 12/19/06, effective 7/1/07.]
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