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