The requirements of this standard apply to underground areas only.
(a) Areas within 25 feet of the following shall be free of combustible materials:
(b) This standard does not apply to installed wiring or timber that is coated with at least one inch of shotcrete, one-half inch of gunite, or other noncombustible materials with equivalent fire protection characteristics.
053-3 Wyo. Code R. § 57.4160