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TPO vs. Modified Bitumen: What to Choose?


The two most commonly used roofing systems in commercial properties are TPO and modified bitumen. Modified bitumen roofing has been around since the 1970s and TPO developed later in the 1990s but they both are ideal for all types of weather and have advantages and disadvantages.

TPO vs. Modified Bitumen: What to Choose?

Modified Bitumen Roofing

Modified bitumen systems are practical and lower in cost than other commercial roofing options. Bitumen was an upgrade from traditional systems and offered enhanced longevity and flexibility, but many contractors have stopped offering these systems due to a number of disadvantages that were recently discovered. Modified bitumen roofing was designed to improve the original version by adding substances like APP (atactic polypropylene). This made sure that the newer systems were resistant to UV light, oxidation, cracking, and blistering. Unfortunately, some manufacturers do not use enough APP to save money and this means the modified bitumen roofing doesn’t stand up to newer challenges as well as expected. The granulated surface of these systems was also added to provide additional UV resistance, but makes it more difficult to identify cracks and leaks in the surface. These roofs also come with a serious fire hazard if there are any open flames nearby during installation.

TPO Roofing

Thermoplastic Polyolefin (TPO) roofing is the more modern choice in large-scale roofing and is installed typically in one of three ways; ballasted, mechanically fastened, and fully adhered. It has become popular because of the numerous benefits for building owners.
The single-ply membrane is tear resistant, UV resistant, and resistant to chemical and grease spills. They are also fully recyclable which is popular with today’s more eco-friendly society. There are also no plasticizers in the insulation which adds to it’s “green” image and appeal. You can also pick from an assortment of colors to match your building or opt for the traditional and energy-saving white. If the current roof is in good condition, you can apply TPO over existing metal or bitumen roofing. You save money and time because you don’t have to tear off and dispose of the old roofing. TPO is also reheatable and has a smooth and easy-to-clean surface as compared to the granules of bitumen roofing. TPO membranes are much thicker material which protects your roof from falling debris and tears.
You must always ensure that your roofing system is installed correctly as most of the problems detected with TPO systems have to do with poor installation. With quality and an experienced roofer that installs the system and welds the seams correctly, you can be assured that your TPO roofing will be more effective and will last longer than expected.

Whichever roofing material you decide to go with, we have the expertise and resources to get your new commercial roofing installed with quality and efficiency. TPO is the preferred option but we understand that sometimes traditional materials are great too. We are here to answer any of your concerns regarding your next roofing project and find the best fit for your roof.


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