TPO (thermoplastic polyolefin) is a single-ply membrane that dominates commercial roofing for good reason: bright white reflectivity cuts cooling loads, heat-welded seams are stronger than the membrane itself, and manufacturer NDL warranties run 20-30 years. We install GAF EverGuard, Carlisle Sure-Weld, and Firestone UltraPly systems as factory-certified applicators.