(1) The interior finish of all walls and partitions must have a flame-spread rating not exceeding two hundred except as otherwise specified in this section. The flame-spread limitation does not apply to:
- (a) Molding, trim, windows, doors, or series of doors four feet wide or less;
- (b) Permanently attached decorative items such as pictures or accent panels constituting a maximum of ten percent of the aggregate wall surface in any room or space or more than thirty-two square feet in surface area, whichever is less.
- (2) All ceiling interior finish must have a maximum flame-spread rating of two hundred, excluding molding and trim two inches wide or less.
- (3) Furnace and water heater spaces must be enclosed by walls, ceiling, and doors having an interior finish with a maximum flame-spread of twenty-five.
- (4) Combustible kitchen cabinet doors, countertops, exposed bottom and end panels must have a maximum flame-spread of twenty-five. Cabinet rails, stiles, mullions, and toe strips are exempted.
- (5) Exposed interior finishes adjacent to the cooking range must have a flame-spread of fifty. Adjacent surfaces are the exposed vertical surfaces between the range top and the overhead cabinets or ceiling and within six horizontal inches of the cooking range.
- (6) Finish surfaces of plastic bath tubs, shower units and tub or shower doors must have a flame-spread of two hundred.
[Statutory Authority: RCW 43.22.340, [43.22.]355, [43.22.]360, [43.22.]432, [43.22.]440 and [43.22.]480. WSR 96-21-146, § 296-150C-1100, filed 10/23/96, effective 11/25/96.]