A thermoplastic is a plastic that melts to a liquid when heated. Thermoplastics are elastic and flexible and in fact, can go through melting/freezing cycles repeatedly. This quality makes thermoplastics recyclable.
In the roofing industry, thermoplastics are more commonly known as single-ply roofing membranes either PVC (Poly Vinyl Chloride) or TPO (Thermoplastic Poly Olefin) heat-welded systems.
PVC’s and TPO’s differ from thermosetting polymers (E.P.D.M.) as they can be remelted and remolded, thus making repairs or alterations to the roof system quite easy.
The PVC Roofing Systems began in Europe in the early 60’s. The reinforced, hot-air fused, reflective single-ply roofing system has been applied in the United States since the early 1970’s with the same successful track record. These systems can be mechanically attached or fully-adhered.
TPO Roofing Systems, much like its ancestor PVC, is a reinforced, heat-welded, single-ply roofing system. It provides a middle ground between PVC and EPDM (rubber) in price and performance. It adds the seam integrity of a PVC System while retaining a lower initial cost of an EPDM. This system can be mechanically attached or fully adhered.
- Johns Manville