Thermoplastic Polyolefin (TPO) and Poly Vinyl Chloride (PVC) are thermoplastic roof systems that are both white and highly reflective roof membranes. These roofs provide excellent weathering characteristics and are highly resistant to ultraviolet light and most chemicals. The membranes have a reinforced scrim and are puncture and tear resistance. Thermoplastic roofs have outstanding seam strength due to the fact the sheets are welded together using hot air. These types of roof systems are lightweight and well suited for second generation (roof-over) applications.