TPO

The top layer, which is often white, is formulated with non-halogen flame-retardants , UV stabilizers, antioxidants and pigments (titanium di-oxide). The bottom layer is generally polymer-rich. The white top layer reflects sunlight and prevents thermal heating inside the building, thereby reducing air conditioning costs. TPO membranes are heat welded directly on the roof to form large sheets. This process eliminates the need for expensive solvent based adhesives that are commonly used in other single-ply roofing.