What is TPO?
As we continue to explore roofing substrates through our “What is a Substrate?” blog series, we will now take a look at one of the most common substrates in commercial roofing. In this week’s blog we will answer the question, “What is TPO?”
Thermoplastic polyolefin (TPO) roofs consist of a single-ply membrane with seams that are usually heat-welded. It is made up of polypropylene, a chemical compound known for its elasticity and durability. This is commonly used in the manufacturing of a slew of industrial and household products.
TPO can be used on residential buildings but is used on commercial buildings more commonly. In this blog, we will look at its advantages and disadvantages. We will also explore how Progressive Materials’ Silicone can help when these roofs show signs of failure.
Advantages
One major advantage is that TPO is relatively easy to install. Its membranes are manufactured in large sheets and sent to contractors in large rolls that can be unfurled on the roof. Those large sheets can be quickly attached to the roof using fasteners, adhesives, and/or heat-welding.
A TPO roof’s heat-welded seams are flexible but strong. Reinforced membranes can handle a building’s thermal expansion and contraction more effectively than other single-ply roofing products. Additionally, its heat-welded seam strength is 3 to 4 times that of EPDM adhesive and tape seams. This makes these roof types a great candidate for new commercial buildings.
Disadvantages
The most widely cited disadvantages of TPO roofs are that the heat-welded seams can rip apart, flashings can fail, and the membrane can become punctured. Any of these problems can allow water into the building. These leaks, if not repaired, will rapidly break down the substrate and the underlying decking. Many TPO roofs never reach their expected life span because of these problems.
Another disadvantage is that TPO is a young roofing technology and has not been proven as a long-term solution. It was introduced in the 1990s, and manufacturers are still looking for the chemical formula that will make the product more durable. According to TPOroofing.org, TPO membranes have been noted to have an issue of accelerated weathering. This problem has been specifically documented in the Southern states that get a lot of heat and sun throughout the year.
How PM Can Help
Like with EPDM roofs, the seams are the main trouble area for TPO roofs. PM Silicone creates a completely seamless membrane on top of the failing substrate, alleviating all seam-related issues.
Additionally, TPO formulas have been known to fail under constant heat. PM Silicone is formulated to reflect the sun’s UV rays and doesn’t break down in extreme heat. It, like TPO, has elastic properties that allow it to expand and contract with the seasons.
In conclusion, TPO’s benefits show it can be a good choice for any new commercial building. But as weather and aging take its toll, PM Silicone can help by restoring these roofs and making them last decades longer.
Please follow along next week as we look into concrete roofs in our “What is a Substrate?” series.
