TPO Roof: Pros and Cons of TPO Roofing

One of the fastest growing roof types for flat roofs, particularly on commercial buildings, is TPO roofing. This inexpensive, thin roofing material is gaining popularity amongst building owners that want a durable, reflective roof, that won’t break the bank.

What Is a TPO Roof?

TPO stands for thermoplastic polyolefin, a single-ply roofing membrane that covers the surface of the roof. The name is a bit misleading, because rather than being a plastic, TPO is actually one of a few different types of rubber, usually a blend of polypropylene and ethylene-propylene rubber.

TPO Roofing Pros

The biggest positive to installing TPO roofing on your flat roof is the cost. TPO is one of the cheapest materials on the market today, costing less than EPDM or other types of rolled rubber roofing. The other biggest positive to using TPO is its color. This type of roofing is white on top, which can help to reflect the sun’s light and stop heat buildup within the building.

Other positives include the fact that you have choices in how it is installed; it can be attached with adhesives or fastened directly to the roof deck. It can also be heat welded in places around chimneys and other protrusions. Finally, TPO resists corrosion and break down upon contact with numerous materials. It also doesn’t promote mildew or algae growth and doesn’t require pressure washing.

TPO Roofing Cons

Unfortunately for those that are looking into TPO roofing, the list of cons far outweighs the positives. While it is inexpensive and white, different manufacturers of TPO products can make wildly different products. This means that you may get a good quality roof from one manufacturer, but for the same price you can find one that is very poorly constructed from another. Added to this confusion is the fact that the material comes in a wide range of different thicknesses. Some buyers may mistakenly believe that the thicker materials are better quality and will last longer. Unfortunately this is not the case; thickness has little to do with the durability of this material, and it all wears out at about the same rate. TPO compounds have changed in recent years, so it is impossible to say how long current roofs will last, but a general estimate puts a TPO roof between 10 and 20 years.

This is due in part to the fact that the top layer of the material is laminated. Laminating any material introduces weak points that can cause the material to shrink, crack, craze, and deteriorate over time. In fact, it is common for some cheaper TPO roofs to develop cracks in the surface relatively quickly.

Additionally, the rolls that TPO is available in are relatively small, width-wise. So while you may purchase a hundred feet of material, you are likely to have seams every 6 – 8 feet. These seams can mean a potential place for the membrane to expand and contract, which can eventually cause the seams to come loose and for water to infiltrate the roof.

Opting for TPO

If you choose to purchase a TPO roof, put your research into the manufacturer to find one that has a warranty or track record that can hold up over time.