What are the Best Roof Materials for a Flat Roof?
TPO, EPDM, modified bitumen, and standing seam metal are the top flat roof materials. Each has different benefits and lifespans—ranging from 10 to 50+ years. At Dolan Roofing & Construction, we’ve helped hundreds of property owners in San Antonio choose the best flat roofing system based on their building type, budget, and long-term goals.
Learn More About the Best Materials for Your Flat Roof Replacement
Flat roofs are common in commercial roofing due to their practical benefits and cost efficiency in terms of materials. However, the low pitch means these roofs are sensitive to drainage issues and must be installed carefully—and using the best material will make all the difference in the lifespan of a flat roof.
Our experienced commercial roofing experts have installed hundreds of flat roofs over the years. Here are the best material options for flat roofing systems, as well as how long you should expect your flat roof to last.
Best Flat Roof Materials Compared
The best and most common flat roofing materials tend to be TPO, EPDM, modified bitumen, and metal roofing. Here’s some more info about each of these.
TPO Roofing
TPO, or thermoplastic polyolefin, is one of the most popular commercial roofing materials available on the market. As a single-ply membrane, TPO is lightweight and easy to install, yet durable. Its heat-welded seams allow for excellent water resistance, and it’s also highly customizable, including lighter-colored options that can help keep your building cool.
At Dolan Roofing & Construction San Antonio, we use Mule-Hide for TPO roofing applications, one of the top manufacturers in the business.
EPDM Roofing
Another single-ply membrane option is EPDM (ethylene propylene diene monomer). EPDM is a durable material made from synthetic rubber. Its rubbery qualities make it especially impact-resistant, which makes it a particularly good material for resisting hail damage.
EPDM has a similar life expectancy to TPO, but it can last much longer if the seams (which are not heat-welded) remain intact.
Modified Bitumen
Unlike TPO and EPDM, modified bitumen roofing is not a membrane, but rather several materials layered together, then unrolled and installed using blowtorches.
The surface of modified bitumen is generally asphalt-based, and in many ways this is a more modernized version of built-up roofing, which was once highly popular for flat roofs but has since fallen out of favor.
Metal Roofing
Where all the above materials are relatively lightweight, inexpensive, and quick to install, metal roofing is none of these. However, metal roofing, and especially standing seam metal roofing, is perhaps the best material when it comes to constructing the most durable flat roof possible.
Metal roofing is resistant to just about every form of inclement weather, with numerous coatings available to provide resistance to perhaps its only real enemy: rust. Because of this, a professionally installed metal roof will generally last at least 40–50 years, and often longer than that.
Best Flat Roof Materials for San Antonio Buildings
Here in San Antonio, we frequently recommend TPO and metal roofing for commercial applications.
TPO roofing offers the following advantages:
- Affordable and quick to install
- Naturally light in color, so it reflects heat
- Highly water-resistant due to its heat-welded seams
Metal roofing provides several benefits as well, including:
- Superior longevity compared to all other materials
- Incredible durability and resistance to all forms of damage
- Sustainable and energy efficient
However, there is no one-size-fits-all recommendation that will work for every flat roof in San Antonio. It’s best to consult with a roofing expert before making a final decision.
How Long Flat Roof Materials Last (And How to Make Them Last Longer)
Flat roofs may last anywhere from 10 years to more than 50 years, depending on the material used. See the chart below, breaking down the lifespan of common flat roof materials:
| Roof Type | Lifespan |
| TPO | 20-30 years |
| EPDM | 25-50 years |
| Modified Bitumen | 10-20 years |
| Metal | 50+ years |
While these expected lifespans vary, commercial property owners should take steps to ensure their roof lasts as long as possible. This starts with proper commercial roof maintenance throughout the roof’s lifespan.
To maximize the lifespan of your flat roof:
- Schedule regular roof inspections to catch issues early
- Repair any damage promptly before it worsens
- Keep drainage systems clear and clean to prevent pooling or overflow
Need Flat Roof Material Recommendations? We Can Help!
At Dolan Roofing & Construction, we have years of expertise in flat roofing solutions. We can provide a thorough assessment of your unique roofing situation and give you a full rundown of the options we think would best suit your needs.
And once you’ve made your decision, we have the expertise and skillset locally in San Antonio to install your new flat roof! Contact us today to get started.
