S.C. Code § 5-25-770
Combustible floors under coal ranges and similar appliances without legs such as are mentioned in Section 5-25-780, in which hot fires are maintained, shall be protected by a sheet of metal or a one-eighth inch layer of asbestos building lumber, which shall be covered with not less than four inches of masonry set in cement mortar. Such masonry shall consist of one course of four-inch hollow terra cotta, at least one of which shall be hollowed and be laid to preserve a free circulation of air throughout the whole course. Concrete may be substituted for a course of solid brick if desired. The masonry work shall be covered by sheet metal of not less than No. 26 gauge, so arranged as not to obstruct the ventilating passages beneath. Such hearths shall extend at least twenty-four inches in front and twelve inches on the sides and back of the range or similar heating appliance. All coal stoves or ranges, with legs, shall be set on incombustible material, which shall extend at least twelve inches in front.
S.C. Code § 5-25-770