This code applies to special contractors installing or applying various types of acoustical or thermal insulating matierals in buildings or within building walls. The materials used are the flexible type in the form of blankets or quilts; loose fills or mineral substances in granulated, powder, cellulose or fiberous wood forms; pads and bats of mineral wool; slabs of corkboard or wood fiber; or rigid type such as wood and sugarcane fiberboard and the reflective type often consisting of aluminum foil encased in paper.