DynaWeld Cap 250 FR is a fire-resistant modified bitumen sheet incorporating the features of a polyester mat with a blend of SBS rubber, fire-retardant additives and high-quality asphalt. The elastomeric asphalt blend has full recovery properties after 100% elongation and lends elasticity and flexibility to the sheet. The covering layer of ceramic-coated roofing granules provides durability along with superior resistance to damage from weather and foot traffic. The polyester mat provides excellent toughness, tensile strength and puncture resistance, and it can accommodate stresses created by typical rooftop expansion and contraction forces. The back of the sheet has a polyolefin burn-off film for ease of heat welding.