At Chaffee Roofing we know a lot of clients with PVC roofing. Depending on what your unique requirements are, PVC can be a great choice. However, many times, alternative products like TPO are a better solution for a lower cost.
Recently we received a call from a potential client looking to install a new roof. The client was deciding between PVC or TPO roofing. When deciding between the two, it can be a difficult choice since both are white, heat welded products.
“When shouldn’t I choose PVC roofing?” he asked.
For some roofs PVC is a good option, where on others an alternative would be the better option. We got to thinking, and to help any client looking for answers, we put together a few pointers.
It is not easy to repair PVC
PVC formulations differ from manufacturer to manufacturer. This means that some PVC membranes are not compatible with other PVC membranes, and therefore will not weld together. In some cases, if a manufacturer goes out of business or makes significant formula changes, the membrane you install today may not be available down the road.
Also, unlike TPO and EPDM, PVC is not compatible with a lot of peel and stick or self adhered patching products. As a result, a white EPDM or TPO self adhered patch will typically not adhere properly to a PVC membrane. As a rule of thumb, the only way to patch or flash to a PVC roof is to weld it with compatible PVC.
PVC does not like the cold
If you live in a cold climate area, as most of us do in New England, then PVC may not be for you.
Most PVC membranes can shatter in cold, icy conditions. You will need to use reinforced PVC membrane to prevent the entire roof from shattering. Even when using reinforced PVC, shattering can still happen, though it will not spread across the roof.
TPO and EPDM membrane do not have this problem.
PVC shrinks over time
Another consideration for long-term planning is that PVC shrinks over time. The membrane pulls away from the surrounding walls and outlets on the roof. Welds spilt and you will have leaks into the building below. This can lead to costly repairs down the road.