Deciding which roofing system is best for a flat-top building isn’t an easy decision, whether it’s a replacement or a new build. For one thing, in today’s environment, any action that requires a major financial outlay deserves careful consideration. For another, there are several roofing system options, and choosing the right one demands a basic understanding of every aspect of the product, from the type of material to the quality of the warranty. In this article, we uncover the advantages and disadvantages of TPO vs EPDM roofing systems.
TPO vs EPDM Roofing: Advantages and Disadvantages
While there are several roofing systems for flat-top and low-slope commercial buildings, two popular choices are EPDM and TPO membranes. Both feature unique characteristics that make them a good value. What sets them apart from other roofing systems is the way they are manufactured and installed. Rubber membranes are produced in large sheets and delivered in rolls for installation.
EPDM and TPO roofing systems are designed specifically for flat top/semi-flat commercial buildings. These materials are excellent choices due to their performance characteristics and fast installation (compared to other systems).
Lightweight and long-lasting, TPO and EPDM roofing membranes are less costly to install than many systems, especially metal roofing. Both are durable and cost-effective. And both are composed of three layers to give you the greatest value for your physical asset budget:
EPDM Layers
- Top Layer: Fiber-reinforced polyester for strength
- Middle Layer: Fire retardant for safety
- Base Layer: Elastomeric for greater flexibility
TPO Layers
- Top Layer: UV blockers/abrasion-resistant compounds for greater durability
- Middle Layer: Polyester mesh for strength and structure
- Base Layer: Flexibility/adhesion compounds for resilience
To help you make the right choice for your building — EPDM or TPO — here are some advantages and disadvantages of each system for you to consider.
Advantages of EPDM Roofs
EPDM (Ethylene Propylene Diene Monomer) is a single-ply, synthetic rubber composed primarily of natural gas (ethylene) and oil (propylene). Cost-effective to install and energy efficient, EPDM has been a popular commercial roofing choice for close to 40 years.
Installation
EPDM comes in large sheets which are rolled onto the surface. It can be mechanically attached or chemically adhered to the roofing deck. Seams are sealed with tape or liquid adhesives.
While TPO and some other roofing types require electricity to install, laying EPDM doesn’t require an electrical source. Installation is fast and efficient, vastly reducing labor costs. Adding ballast during installation makes EPDM even more durable.
Longevity
EPDM is known for lasting longer than comparable systems, up to 20+ years. This rubber roof is a cost-efficient choice when you consider how long it lasts and how easy it is to install and repair in case of damage.
Flexibility
EPDM membranes are flexible, allowing the material to adjust as the building settles — a real advantage over other roofing systems.
Energy Efficient
Available in white and black, EPDM helps save on energy costs while conserving resources. White EPDM helps keep the building cool in warmer climates by reflecting solar rays. Black EPDM absorbs solar heat to keep the structure warm in cooler regions.
Environmental Resistance
EPDM resists damage from environmental stressors. It won’t crack in freezing temperatures, can withstand the impact of hailstones up to 2 inches in diameter, and is UV-radiation resistant.
Lightweight
Because EPDM is light, the roof deck doesn’t require reinforcement to support the roofing material.
Disadvantages of EPDM Roofs
Aging
EPDM becomes less durable as it gets on in years. Inspecting the roof will help you stay ahead of problems.
Cost
In most cases, EPDM can be slightly more expensive than TPO.
Leak Susceptibility
One of the primary weaknesses of EPDM is that the seams between the rolls can allow water in.
advantages of TPO Roofs
TPO (Thermoplastic Polyolefin) is seen by many in the industry as another form of EPDM. Yes, they are both membranes, and they are both easy to install, but some differences will likely influence your decision.
Like EPDM, TPO is a single-ply reflective membrane engineered for flat-top and semi-flat commercial buildings. TPO, a relative newcomer compared to EPDM, is growing in popularity. This surge of interest is probably due to the cost: TPO is the least costly of all rolled rubber roofing options.
Installation
TPO is delivered in large rolls, simplifying the installation process. But unlike EPDM, you have choices on how to install it. TPO can be attached with adhesives or fastened directly to the deck.
In cases with protrusions, such as flashing to work around, the membrane can be secured by heat welding. TPO is pliable and easily worked, aiding installation.
Environment Resistant
Superior at withstanding the effects of ozone and UV rays, TPO also resists mold growth, dirt accumulation, tears, and punctures.
Energy Efficient
The white surface of TPO makes it ideal for reflecting solar energy to contribute to more efficient cooling while reducing energy costs.
Shrinkage Resistance
TPO is a stable membrane and not prone to shrinkage, allowing seams and edges to remain intact.
Less Prone to Leak
Unlike EPDM, TPO has smaller seams, making them less susceptible to leaks as the membrane ages.
Puncture Resistance
TPO offers three times more protection against punctures than EPDM.
Disadvantages of TPO Roofs
Longevity
TPO is a relatively new product. As such, manufacturers are still working to discover the best mix of properties to ensure durability and a long lifespan. Some formulations may not last much beyond the 10-year mark.
Heat-Welded Seams
Heat-welding seams demand high-quality installation expertise.
Aging
As TPO ages, it loses flexibility and can crack open, reducing its lifespan.
Should you install a TPO or EPDM roofing system?
Considering all the advantages and disadvantages, EPDM and TPO rubber membrane roofing give you years of satisfactory performance. Both are easy to install and repair. But at the end of the day, the bottom line is these membranes are among the most economical to purchase and install without incurring high labor costs.
TRUST THE EXPERTS AT MCKINNIS
If you are in need of roofing, windows, siding, or gutter work, give us a call today at 402-426-2644, visit our website at www.mckinnisinc.com, or fill out our contact form. Our roofing and exterior experts are highly trained and always ready to help!