(a) Except as provided in this section, deck coverings used for leveling or finishing purposes in control spaces, stairway enclosures, passageways, accommodation spaces and service spaces must be noncombustible.
- (1) Materials approved under § 164.006 in subchapter Q of this chapter may be used in thicknesses not to exceed the approved thickness.
- (2) Combustible deck leveling and finishing materials which are not approved under § 164.006 in subchapter Q of this chapter may be used in a thickness not to exceed 9.5 millimeters (.375 inches).