DynaPly® T1 is an elastomeric modified bitumen sheet incorporating the features of a strong composite fiber glass/polyester mat. The composite reinforcement is coated with a blend of SBS rubber and high-quality asphalt. The elastomeric asphalt blend has full recovery properties after 100% elongation and lends elasticity and flexibility to the sheet. The inorganic fiber glass reinforcement, in conjunction with the polyester, provides stability, toughness and puncture resistance to the product, and resists moisture absorption. The reinforcement also provides high tensile strength and affords better natural resistance to the other factors which affect roof performance. This product does not have a surface finish and must be used in constructions that will provide protection from UV (ultraviolet light) and the elements. A fine mineral parting agent is applied to both sides of the product.