Thermoplastic polyolefin (TPO)
Thermoplastic polyolefin (TPO) is the fastest-growing segment of the commercial roofing industry. TPO membranes are single-ply roof membranes constructed from ethylene propylene rubber. They are designed to combine the durability of EPDM rubber with the proven performance of hot-air weldable seams. They have been tested as having excellent resistance to ozone, are algae-resistant, environmentally friendly and safe to install. The material’s manufacturers are so confident in properly welded seams that the material is sometimes advertised as a monolithic (seamless) roof. Seam strengths are reportedly 3 to 4 times those of EPDM’s adhesive and tape seams.
Thermoplastic polyolefin is highly resistant to tears, impacts, and punctures with good flexibility to allow for building movement. Thermoplastic polyolefin are available in white, light gray, and black with thicknesses of either 45 mils (.045″) or 60 mils (.060″). The width of the membrane depends on the manufacturer but they usually come in widths of six to six-and-a-half feet and are one-hundred feet in length.
Thermoplastic polyolefin membranes are installed fully-adhered, mechanically-attached or ballasted. Fully-adhered means that the roof is “glued” to the substrate using a special adhesive. What actually happens is the glue creates a chemical bond with the membrane.