Modified membranes are asphalt-based and are typically found installed with one or more base underlying interplies. This is the most common system for residential roofs. Modified products are typically either smooth surfaced, granule surfaced or foil-faced. Additionally, they may be field surfaced with a coating or a flood coat of asphalt and aggregate. The typical lifespan for modified roofs are relatively low at 9-15 years.
Thermoplastic Membranes – These single-ply membranes are composed of polymers, which soften when heated and harden when cooled. This process is repetitive provided the material is not heated above the point at which decomposition occurs. These membranes can usually be hot air welded throughout their service life.
There are many different types of Thermoplastic Membranes including the following:
TPO (Thermoplastic Olefin) – Lifespan = 15-25 years when maintained
PVC (Polyvinyl Chloride) – Lifespan = 15-20 years when maintained