Thermoplastic roofing membranes are single-ply and can be installed using a variety of methods, the most common installation methods being mechanically attached and fully-adhered. Thermoplastic refers to a synthetic substance that is softened when heated, but hardens upon cooling. This roofing material can be fully adhered, mechanically fastened, or ballasted. TPO seam strengths are reported to be three to four times higher than EPDM roofing systems.
This is a popular choice for "Green" building as there are no plasticizers added and TPO does not degrade under UV radiation. It is available in white, grey, and black. Using white roof material helps reduce the "heat island effect" and solar heat gain in the building.
The Mechanically Fastened/Attached System uses fastening plates to secure the membrane. This system provides faster installation times without the use of adhesives and seam tapes. Membrane seams are then heat-welded with specialty hot-air equipment. Mechanically attached is the most prevalent method of installing TPO membranes.
Mechanically attached systems carry warranties of up to 25 years.
The Fully Adhered System uses TPO bonding adhesive to adhere and secure the TPO membrane to the insulation board or recovery board. This method does not require the use of fastening plates to secure the membrane. Membrane seams are then heat-welded with specialty hot-air equipment.
Fully adhered systems carry warranties of up to 30 years.
A ballast roof system is a loose-laid roofing system that is not anchored or adhered to the decking, except for the perimeter and around penetrations/curbs, and is ballasted throughout, generally with gravel. Ballasted is the least prevalent method of installing TPO membranes and is used less and less today.
TPO roofs are durable; resisting dirt, bacteria, algae and debris build-up. It's flexibility makes it highly resistant to tears, punctures and impact damage. This flexibility also allows for a building’s movement and setting, without compromising the roof’s performance. Hot-air welded seam strengths are as much as 3-4 times greater than EPDM adhesive and tape seams.
One of the factors that makes TPO roofing attractive both in residential and commercial construction is its reasonable cost. Being a less labor-intensive installation process, the overall cost of a TPO replacement system is often times less costly than other commercial roofing systems.
The solar reflective properties of white TPO roofs contribute to reduction of energy waste from HVAC systems. Moreover, reflecting sun’s ultraviolet rays leads to the mitigation of the heat island effect in urban areas and contributes to cooler interior temperatures inside. Also, TPO is one of the few 100% recyclable roofing materials available.