TPO Membranes Are More Environmentally Sound and Cost-Effective Way of Sealing Roof

Until about 25 years ago, buildings with flat roofs were paved with tar or asphalt to protect from leaks and to move water along the surface of the roof. Today, Thermoplastic Olefin (TPO) membranes are a more environmentally sound and cost-effective way of sealing a roof. Composition TPO membranes are constructed from ethylene propylene rubber and filler materials such as talc, carbon filler or fiberglass. Ethylene, an organic gaseous substance, and propylene, a byproduct of petroleum refining, are polymerized (bonded together by chemical reaction) with rubber with state-of-the-art technology. The filler materials are added to reinforce the membranes for construction use. The membranes come in white, grey or black and in 45 or 60 millimeter thicknesses. Sizes vary, but in general the panels are 6 feet long and up to 100 feet wide. Function Each TPO membrane is single-ply, flexible, and durable. The seams are weldable with hot air. The membranes have excellent ozone resistance, are algae-resistant and are long-lasting and environmentally sound. A TPO membrane roof is very resistant to tears, punctures and impact damage. The flexibility also allows for building movement and settling. Installation TPO membranes can be installed in three different ways: Fully adhered, mechanically attached, or ballasted, according to Roof Help. When fully adhered, the membranes are glued to the sub-roof using a special adhesive that creates a chemical bond with the TPO. Mechanically attached panels are secured with screws or other fasteners. Ballasted membranes are laid loosely over the roof and then sealed around all edges. A ballast consisting of river stones 2 to 3 inches in diameter is placed on the membranes at about 1000 to 1200 pounds of pressure per roof square (100 square feet). Sometimes concrete pavers are used instead of the stones. These average 20 pounds per square foot. Source: ehow.com