Single Ply, Simplified
- Mar 19
- 5 min read
Updated: Apr 8
Differences and benefits of TPO, PVC, and EPDM
Three membranes. Decades of proven performance. One question that trips up even experienced design teams: which one is right for this project?
Single-ply roofing is exactly what the name suggests: a single membrane layer, engineered to waterproof and protect a low-slope roof. Unlike modified bitumen systems that require multiple plies, single-ply membranes do the job with just one sheet. Today, it’s the dominant roofing system on low-slope commercial buildings across the United States.
There are three main membrane types: TPO, PVC, and EPDM. Each has a distinct chemistry and a distinct set of strengths. Choosing between them is less about which one is “best” and more about understanding which one is best suited to the specific demands of your building and budget.
This guide gives you a breakdown so you can choose the right fit for your project.
TPO (Thermoplastic Polyolefin)
Reliable & Cost-Effective
Known for its exceptional durability, energy efficiency, and cost-effectiveness, TPO is the most widely installed single-ply membrane in North America today.
TPO is a thermoplastic, which means it softens when heated and hardens when cooled. As a thermoplastic, sheets are rolled out, heated, and pressed together, fusing into a bond that's actually stronger than the membrane itself. When installed properly, the membrane essentially becomes seamless across the entire roof surface. It's also highly resistant to tears, punctures, and impact, and has become a reliable go-to for large, straightforward commercial roofs.
It comes standard in white, but is also available in grey and tan. White TPO’s reflective surface boosts energy efficiency by bouncing UV rays and solar heat away from the building, resulting in lower cooling costs and energy loads.
TPO can be mechanically fastened, adhered, self-adhered, or induction welded, with the majority of systems being mechanically fastened for greater cost effectiveness. Compared to EPDM (which we'll cover later), TPO membranes are more rigid, which may also help you achieve greater wind uplift performance, especially with fastened systems.
Best Suited For: Warehouses, distribution centers, big-box stores, and any buildings with a large footprint where budget is a priority; and roofs with high wind uplift requirements.
Keep in Mind: Not suited for rooftops with grease, oil, or chemical exhaust (spoiler: check out PVC instead). Not recommended for ballasted roofs. TPO installation requires specialized hot air welding machines and well-trained crews to execute properly.
PVC (Polyvinyl Chloride)
Excellent Chemical Resistance
If the building has a commercial kitchen, sits next to a runway, or handles industrial processes, PVC is almost always the answer.
Like TPO, PVC is a thermoplastic, offering the same weldability and speed-of-install advantages. However, PVC has a larger welding temperature window and is more flexible than TPO, making it easier to work with on complex flashings.
What really sets PVC apart is its plasticizer formulation. Its plasticizers make it inherently resistant to grease, oils, fuels, and industrial pollutants (exposure that will degrade TPO or EPDM over time). PVC is also fire-retardant and self-extinguishing, which is why it’s frequently used at airports, where it can withstand jet fuel exposure without breaking down.
The Johns Manville PVC formulation uses Dow® Elvaloy™ KEE, a solid plasticizer that bonds with the PVC to provide consistent plasticizer retention. This maintains high flexibility and durability throughout the life of the roofing system. While some PVC membranes can become brittle over time, Johns Manville PVC never loses flexibility.
Best Suited For: Restaurants, food and beverage processing plants, manufacturing facilities, airports, stadiums, and high-value buildings where longevity justifies the premium.
Keep in Mind: Higher material cost than TPO. Not intended for ballasted systems. Like TPO, PVC requires specialized equipment and trained crews for installation.
EPDM (Ethylene Propylene Diene Monomer)
Rubber Roofing
EPDM is a synthetic rubber membrane that has been in use for more than 60 years. Single ply roofing contractors often start their careers with EPDM as the material is easy to work with and doesn't require any specialized equipment for installation.
Where other membranes can become brittle or fail under significant temperature swings, EPDM's rubber composition stays flexible, expanding and contracting with the building without stressing the membrane. That makes it particularly well-suited for northern climates and large roofs where thermal movement is a constant consideration.
Unlike TPO and PVC, which are thermoplastics, EPDM is a thermoset material, meaning its molecular structure is permanently set during manufacturing. As such, seams are adhered or tapered instead of welded. Pre-taped factory seams are available and can cut installation time significantly.
JM EPDM is available in both black and white, and in non-reinforced and reinforced versions. JM also offers a self-adhered option that requires no VOC-containing adhesives, making it a great choice for occupied buildings or projects with air quality requirements.
What sets JM EPDM apart is how it is made. JM extrudes its EPDM sheets, producing a thicker membrane with a more uniform surface finish, resulting in less field preparation, stronger bonds at seams and flashings, and a cleaner installation overall.
In addition to being fastened or adhered, EPDM can be ballasted for a faster, more economical installation.
Best Suited For: Industrial buildings, large commercial footprints, and projects in northern climates, and any project where long-term performance and low-maintenance service life are the primary goals.
Keep in Mind: Standard black EPDM absorbs heat rather than reflecting it, which is a drawback in warmer climates or for buildings with high cooling loads. White EPDM addresses this. EPDM isn't ideal where rooftop exhaust contains oils (they affect the rubber chemistry).
At a Glance: Side by Side Comparison
TPO | PVC | EPDM | |
Material | Thermoplastic | Thermoplastic | Rubber |
Installation Methods |
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Available Colors |
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*Energy Savings membranes Not all colors are available as standard stocked items in all size configurations. |
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Relative Cost | $ | $$ | $ |
Ideal Applications | Warehouses, big box stores, strip malls | Airports, restaurants, manufacturing plants | Large footprints, northern climates |
Remember: the roof is a system and the membrane is only one part of it. Insulation, cover boards, installation quality, detailing, and owner maintenance all play a role in how a roof actually performs over time.
So, which one is right for your project?
There's no universal answer, but the right membrane usually becomes clear once you factor in the building's use, its environment, your budget, and any design or performance requirements. Here's a simple way to think about it:
Consider TPO if the roof is large and straightforward, with no significant chemical or grease exposure, and you want a reliable system at a competitive price.
Consider PVC if the building has a kitchen, handles industrial processes, or sits at an airport. Chemical and grease resistance are non-negotiable.
Consider EPDM if the building is in a cold or high-variation climate, or the roof is large and flexibility and durability are top priorities.
We can help you figure it out
At BRT, we represent Johns Manville's full commercial roofing lineup, including TPO, PVC, EPDM, and more. Whether you're working through a spec, pricing a job, or trying to understand your options as a building owner, we're here to help.