| abstract |
A roofing system incorporates a fire resistant asphalt composition comprising a thermoplastic elastomer modified bitumen, a filler, a brominated diphenyl ether, antimony oxide, and zinc borate. The apshalt composition is utilized with and impregnated into at least one layer of fiberglass or polyester mat. Preferably at least two layers are utilized wherein an upper layer is a fiberglass mat and a lower layer is a polyester mat, both mat layers being impregnated with the composition. In its preferred formulation, the asphalt composition comprises, in weight percent, about 30 % to 90 % bitumen, about 4 % to 16 % styrene-butadiene-styrene copolymer, about 10 % to 40 % filler, and up to about 20 % each of the brominated diphenyl ether, the antimony oxide, and the zinc borate. The preferred brominated diphenyl ether is decabromodiphenyl ether. |