TPO vs. Modified Bitumen Roofing Options

TPO vs. Modified Bitumen Roofing Options

When it comes to roofing, you have a lot of options. If your building has a flat roof, then those options matter a lot. There are more than a dozen ways to cover a flat roof, and each comes with its own set of pros and cons.

To help you understand the depth of those options, we’re going to highlight two: TPO and modified bitumen. We’ll explain each of these roofing types so you can see whether one of them might be right for you.

What Is TPO?

TPO stands for thermoplastic olefin membrane. While that sounds complicated, TPO is essentially a rubber roofing material. Because of the rubberlike properties, it is durable, holds up well in sunlight, and is great for protecting flat roofs from water.

TPO is a single-ply roofing material. In fact, it is stored and transported in rolls, so when roofers install it, they essentially unroll it and fasten it.

TPO is still considered a new type of roofing for flat and commercial roofs. It’s been around for more than a decade, but it’s nowhere near as old as plenty of other roofing materials. Despite the relative newness, it is rising in popularity, and it continues to go on more and more new roofs.

Advantages of TPO Roofing

There are very clear reasons why TPO is so popular. Some of them stem from the single-ply design. Since there aren’t multiple layers of TPO on a roof, it requires a lot less material to complete a roofing project. This makes TPO cheaper per square foot than a lot of other materials. It’s also faster and easier to install, which lowers installation costs.

TPO also comes in a white color. This makes it a great solar reflector, and a TPO membrane can dramatically lower cooling costs in a building.

On top of all of that, TPO also needs very little maintenance during its lifetime.


Even with those clear advantages, TPO isn’t the right answer for all roofs. For starters, TPO doesn’t last as long as many other roofing materials. If you want longevity, modified bitumen is definitely better.

TPO is also thin, which means it’s not ideal for roofs with foot traffic or heavy weight. If you want to make use of roof real estate, TPO can’t handle a lot of heavy objects.

Lastly, while TPO is good against weather in general, it is not great in terms of resisting punctures. This means falling tree branches can be a bigger problem for TPO. If your roof is under a lot of large trees, TPO might not be the best choice.

What Is Modified Bitumen?

Modified bitumen is a completely different approach to roofing. It’s still designed for flat roofs, but it doesn’t resemble TPO at all. Around since the ’60s, modified bitumen is an alternative take on built-up roofing.

While TPO is single-ply, modified bitumen uses multiple layers to reinforce the roof structure. There are layers with asphalt, polymers, and/or cap sheets. The various layers are combined to increase elasticity and flexibility while producing strong tensile strength and puncture resistance.

Ultimately, this process makes modified bitumen a very strong roofing option, but it comes with its own set of pros and cons.

Pros for Modified Bitumen

Here’s what’s great about modified bitumen. First, it’s an incredibly versatile roofing option. Many types of roofs thrive in specific climates, but you can use modified bitumen anywhere.

It’s also been around for a long time, so everyone in the industry knows how to work with it. That makes it easier to source than some other roofing materials.

Most of all, modified bitumen is tough and durable. You can expect this type of roof to last anywhere from 10 to 30 years longer than TPO. That’s not a small advantage.


And yet, modified bitumen loses ground to TPO every year, and for good reason. First, it’s a lot more expensive to install. The multiple layers are more expensive than TPO. On top of that, modified bitumen installation takes a lot more effort, so the installation costs are considerably higher.

Because modified bitumen uses petroleum products, the sheer cost of materials fluctuates pretty dramatically.

But most importantly, the design of modified bitumen means that it isn’t great against ponding water. It is essential to install drains in this type of roof, and that can prove to be a challenge in some cases.

Get Your Roof From Paradigm

Paradigm Roofing has been serving the DFW metroplex for many years. We have experience with TPO, modified bitumen, and plenty of other roofing materials. If you need a roof, we can help.

Contact us today. We’ll discuss the many options available to you and ensure that you fully understand the advantages of each option. When you make your selection, we will handle the installation to leave you with an excellent new roof that is built to last.