Stay on top of potential problems with your TPO roof
TPO roofing is a durable, weather-resistant material for flat and low-slope roofs.
TPO roofs must be correctly installed to avoid serious problems.
TPO roofs are prone to leaks, punctures, standing water, and improperly adhered material.
Replacing your roof is a major project, so you want to know as much as possible about the roofing material you choose—both the good and the bad—before you start the job. Thermoplastic polyolefin, or TPO, is a popular material choice for many roofs, but like any material, it can present some problems. Learn about common TPO roofing problems, why they occur, and how to prevent them so your roof stays durable and can protect your home for years to come.
TPO roofing is a waterproof membrane that comes in large sheets of thermoplastic polyolefin that are joined together using heat, fasteners, adhesive, or a combination of those methods. It’s often used on flat roofs, especially on commercial or industrial buildings. For residential use, it’s used on homes with very low-sloped or flat roofs and outbuildings like freestanding garages with flat roofs.
TPO is durable and weather-resistant, making it a good choice in areas with harsh weather. It’s a low-maintenance option that can help with energy efficiency. However, this popular roofing material does have some drawbacks, which can stem from improper installation, not maintaining the TPO roof correctly, or even just the effects of aging material.
TPO roofs can cost more when you compare TPO to PVC roofs or other flat or low-slope roofing materials, but along with the higher price tag comes a longer life span of 20 to 30 years compared to 15 to 20 years for less expensive options.
One of the most common roofing problems with TPO roofs is their susceptibility to punctures and tears from storm debris. Since the material is a single-ply flexible membrane, it doesn’t have the puncture resistance of sturdier roofing materials like shingles. A single puncture can lead to water leaks and larger tears if not immediately addressed by a local roof repair professional.
Damage from people walking around on the roof is another way TPO roofs can get punctured or torn. This damage can occur during roofing installation, repairs of HVAC units or other rooftop utilities, or even if the rooftop is used as a balcony or entertaining space. Foot traffic punctures can be prevented by reinforcing areas that may see frequent traffic.
TPO roofs can leak at the seams where the membrane sheets are joined together. These seams are the weakest point of the roofing material and the most likely to fail, which can lead to unexpected and unwanted water intrusion and roof leaks during heavy rain. If you notice leaks from your TPO roof, it’s best to immediately call a pro who repairs roofs to fix the seams as soon as possible.
The most likely reason a TPO roof will leak at the seams is that the seams weren’t joined properly during installation. TPO sheets are often joined using heat guns, and if the roofer doesn’t follow the correct procedure, the seam can fail. Sometimes, adhesives are used to join seams instead of heat and can weaken or deteriorate if not properly installed.
Another cause of seam leaks is when the TPO material shrinks and expands due to changing temperatures. This puts pressure on the seams and weakens them.
A TPO roof should be smooth and even across the entire surface. Sections that don’t look uniform due to peeling, bubbling, or lifting material are signs that something’s wrong.
Peeling, bubbling, and lifting are almost always signs of a bad roofing job for TPO roof installation. The roof’s surface needs to be clean, dry, and properly prepared before installing TPO. If the roofer hasn’t followed the necessary steps to prepare the roof, the TPO sheets won’t adhere correctly and can lead to problems with the roof’s surface.
TPO is designed to be installed on flat roofs that have a very slight slope and a fully functioning drainage system to remove water from the roof as quickly as possible. Water will pool on the surface if the roof isn’t built with the necessary slope.
Pooling water is a significant concern when dealing with a flat roof. Water accumulation can weaken the TPO material and degrade the seams, leading to leaks, mold growth, and other serious problems.
Deteriorating TPO can also lead to standing water since the membrane can lose its waterproof properties and prevent water from draining properly. Regular inspections will alert you to any areas of deteriorating material so you can address any issues before standing water becomes a problem.
Another common problem with TPO roofs is when the flexible membrane shrinks or warps from its original position. Shrinkage can cause gaps in coverage that allow water to penetrate the roof and contribute to faster material deterioration.
If the TPO material isn’t installed correctly, it may begin to shrink immediately after installation. The membrane sheets must be adhered to the roof’s surface according to the manufacturer’s specs to maintain their original shape.
Extreme heat can cause TPO to shrink. Extended exposure to high heat can make the material stiff and brittle, causing it to lose its flexibility and shrink.
Age is also a cause of shrinkage. It’s important to replace a TPO roof when it shows signs of aging. These roofs can last 20 to 30 years, but extreme weather conditions and lack of maintenance can shorten their life span.
If your roof’s TPO material is punctured during a storm, it can likely be repaired. However, if the material is shrinking due to age, or has extensive damage, it makes more sense to replace it entirely.
Another rule of thumb is that if the TPO repair will cost 50% or more of the cost to replace it, you’re better off going for the replacement. On average, installing a new TPO roof costs $6,500 to $24,000.
