30 C.F.R. § 57.22221

Current through November 30, 2024
Section 57.22221 - Overcast and undercast construction (I-A, II-A, III, and V-A mines)

Overcasts and undercasts shall be-

(a) Of substantial construction;
(b)
(1) Constructed of noncombustible materials; or
(2) Where constructed of combustible materials, the outside surfaces shall be coated with at least one inch of construction plaster containing perlite and gypsum; at least one inch of expanded vermiculite, Portland cement and limestone; or other coatings with equivalent fire resistance;
(c) Kept clear of obstructions.

30 C.F.R. §57.22221