Thermoplastic Polyolefin (TPO) is a thermoplastic roof system that is both white and a highly reflective roof membrane. These roofs provide excellent weathering characteristics and are highly resistant to ultraviolet light and most chemicals. The membranes have a reinforced scrim and are puncture and tear resistant. Thermoplastic roofs have outstanding seam strength due to the fact the sheets are welded together using hot air. These types of roof systems are lightweight and well suited for second generation (roof-over) applications. TPO roof systems account for approximately 38% of commercial roof installations.
Composed of asphalt and reinforced with either polyester or fiberglass, modified bitumen roofs are a blend of traditional and modern roofing technologies. Two different polymers, Styrene Butadiene Styrene (SBS) or Atactic Polypropylene (APP), are used to modify the membrane and impart greater elasticity and temperature flexibility. Since polyester fiberglass fortifies the roof system, it exhibits more strength and resistance to punctures and is typically installed in various layers to provide a multi-tier protection system from water, extreme temperatures and wind uplift.
Modified Bitumen Roof Systems do differ in how they are installed on the roof based on the polymer sheet chosen. SBS, a polymer that gives bitumen characteristics similar to rubber, is typically installed with hot asphalt or cold adhesives. APP, a thermoplastic polymer, is almost always installed utilizing the torch method.
Coatings are an outstanding alternative when a full roof replacement is not required, can extend the life of a roof, and provide a highly reflective surface that may lower roof surface temperatures and ultimately reduce energy costs. Additionally, coatings provide a monolithic application that can form to irregular roof surfaces, as well as seal cracks and splits in the roof surface.
In older metal roofs, problems occur that are caused by the movement and subsequent loosening of the roof system and fasteners over time. Seam separations, loose flashings around penetrations, and rusting metal panels and fasteners can lead to roof failure if regular roof maintenance is not performed. Roof coatings are an excellent solution for metal roof issues.