The most obvious similarity is that TPO (Thermoplastic Olefin) and PVC ( Poly Vinyl Chloride) are both thermoplastic materials. Both membranes are heat weldable, which makes them more resistant to leaks than EPDM, because of a reduced number of instances of seam failures.
Moreover, like PVC, TPO is considered a green roofing material, and can save you money on your electricity bills, because both membranes are white in color and possess reflective “cool” roof properties. What makes them “cool” is the fact that they are both resistant to heat and sun’s ultraviolet rays and are able to keep the inside of your home or office space cooler, reducing the need for excessive AC usage.
Both materials share other important benefits, such as resistance to chemicals, grease and oil. They are puncture resistant and can be easily repaired. Also, both TPO and PVC are designed to be flexible to conform to the movement of the roof.
TPO stands for thermoplastic polyolefin, a single-ply roofing membrane that covers the surface of the roof. The name is a bit misleading, because rather than being a plastic, TPO is actually one of a few different types of rubber, usually a blend of polypropylene and ethylene-propylene rubber.
PVC roofing is made from two layers of PVC roof material with polyester added in between the layers to act as a reinforcement. The layers in a PVC roof include additives to make the material flexible, UV stable, and to prevent curing. By adding a layer of acrylic coating to roof membrane, a PVC roof is made reflective and repellent to dust and dirt.
The most common thermoplastic roof membranes are PVC and TPO. The following provides general descriptions of these two systems.
In terms of weathering (i.e., based on the Heat Aging and the Accelerated Weathering tests), TPO has the clear edge over PVC.
While TPO has superior weathering and slightly better tear and break resistance than PVC, PVC does have some characteristics that certain customers need or prefer. For example, PVC has better chemical resistance; it does not absorb or get weakened by oils and greases. This means that PVC is the preferred membrane for restaurants and other buildings that have grease traps on the roof.