DynaWeld™ Cap 250 is a polyester reinforced SBS modified bitumen sheet. It incorporates the features of a tough polyester mat that is saturated and coated with a blend of SBS rubber and high quality asphalt. The elastomeric asphalt blend has full recovery properties after 100% elongation and lends a high degree of elasticity and flexibility to the sheet. The polyester mat provides excellent tensile strength, toughness, puncture resistance and can accommodate stresses created by typical roof top expansion and contraction forces. The covering layer of ceramic-coated roofing granules provides durability along with superior resistance to damage from foot traffic. The back of the sheet has a poly burn-off film for ease of heat welding.