TPO vs. EPDM: Which Flat Roof is Right for Your Metro Detroit Building?

Why is TPO better than EPDM for flat roofing? 

That’s a common question, and the real answer is: TPO is not universally better than EPDM; it depends on the situation. TPO (thermoplastic polyolefin, a type of vinyl) and EPDM (ethylene propylene diene monomer, a synthetic rubber) are both excellent, reliable solutions for commercial flat roofing systems. However, each material offers distinct advantages over the other in specific conditions. Understanding these differences is key to making the best investment for your Metro Detroit property. 

Key Factors Determining the Best Flat Roof Material: 

1. Installation in Cold Weather Conditions – If you are installing a new flat roof in Metro Detroit during the winter, TPO is the clear winner. 

• EPDM Installation Challenges: EPDM roof installations heavily rely on adhesives and chemical primers. These materials do not perform well in colder temperatures. They require a certain level of warmth and sunlight to cure and bond effectively as designed. 
• TPO Installation Advantage: TPO largely avoids these cold-weather issues (especially for mechanically attached or ballasted systems). TPO uses heat welding to form strong, watertight seams instead of a chemical reaction. The specialized heat guns used for TPO installation are not affected by the same performance limitations as the adhesives used with EPDM. 

2. Resistance to Punctures and Foot Traffic – For commercial roofs with moderate to high foot traffic, such as those accessed by HVAC technicians or used as walk-out areas, we recommend TPO. TPO has a significantly higher puncture resistance compared to a standard EPDM membrane. 

• TPO’s Durability: This increased toughness comes from the internal fabric scrim that the TPO is coated onto. This structural component provides additional durability against dropped tools, sharp debris, or even repetitive shoe traffic, ensuring the membrane stays intact longer. 

3. Chemical and Grease Resistance – Another critical area where TPO outperforms EPDM is in its resistance to grease and harsh chemicals. 

• The Grease Problem with EPDM: Many commercial buildings with flat roofs have kitchen exhaust and grease containment systems installed on the rooftop. Building owners frequently neglect the maintenance of these grease traps. When the grease overflows and contacts the roof membrane, it causes a severe issue for EPDM. The grease chemically interacts with and rapidly breaks down the EPDM membrane, leading to softening,

erosion, and premature failure. This often results in major, costly repairs. 

• TPO’s Chemical Stability: TPO’s chemical composition is inert and does not react with grease. Grease sitting on a TPO roof will simply sit there—it will not cause the membrane to break down or deteriorate. 

Pro-Tip: If your building has a grease containment system, we strongly recommend investing in a TPO roof and enrolling in a regular Roof Top Maintenance Program like the Kanga Kare Club. We schedule quarterly visits to ensure your critical rooftop systems, including grease traps, are properly maintained and prevented from overflowing. 

Conclusion: Making the Right Flat Roof Choice 

Is TPO better than EPDM? Yes, but only in certain, specific situations. There are plenty of scenarios where EPDM remains the superior, more cost-effective product and will outperform TPO. 

Our best recommendation for any commercial building owner is to engage a qualified, local roofing contractor who takes the time to thoroughly inspect your building, understand your specific operational needs (e.g., foot traffic, climate exposure, rooftop equipment), and then determine the optimal material for both immediate performance and long-term durability over the next 20+ years. 

Our team of flat roofing specialists would be happy to provide this professional consultation and service for you. The best way to get the right answers for your building needs is to call us at 586-566-0308 or schedule your inspection online.

Schedule Inspection Now

We truly hope this article has provided valuable insight, and we wish you a Kanga-Rific day! Sincerely, 

Bill Burkhardt, Jr. 

VP of Marketing – Owner 

Four Seasons Kanga Roof