Abstract: A needle punched synthetic fabric of polyester fibers is impregnated with asphalt emulsion which is absorbed in an amount to approximately double the weight of the needled fabric. There is no fiber-free agglomoration of asphalt and the impregnated fabric is flexible and relatively immune to concentrated impact loads even at freezing temperature. It can be made waterproof for a single membrane built up roof by application of asphalt emulsion or hot-mopped asphalt and in such applications has properties acceptable under existing fire simulation tests. Other synthetic fibers such as nylon or polyester-nylon mixes can be used.