Wash. Admin. Code § 296-150C-1120
The bottom and sides of combustible kitchen cabinets over cooking ranges or tops including a space of six inches from the edge of the burners must be protected with at least materials rated at twenty-five or less flame-spread covered with at least twenty-six gauge sheet metal (.017 stainless steel, .024 aluminum or .020 copper) or equivalent protection. The protective metal over the range must form a hood with at least a three-inch eyebrow (measuring horizontally from face of cabinet). The hood must be centered over and at least as wide as the top of the cooking range.
Wash. Admin. Code § 296-150C-1120
Statutory Authority: RCW 43.22.340, [43.22.]355,[43.22.]360 , [43.22.]432, [43.22.]440 and [43.22.]480. 96-21-146, § 296-150C-1120, filed 10/23/96, effective 11/25/96.