TPO vs EPDM Roofing: Which Single-Ply Membrane is Best?

When it’s time to replace the roof on your commercial building or residential home, one major decision is which type of flat roofing material to use. Single-ply membranes like TPO and EPDM have become go-to roofing solutions thanks to their durability, weather resistance, and energy efficiency. But should you opt for TPO or EPDM?

This in-depth guide compares TPO and EPDM roofing systems to help you determine which single-ply membrane is the best fit for your roofing project and climate. We’ll examine the composition, benefits, downsides, and ideal uses of TPO and EPDM so you can make an informed decision when selecting a new flat roofing system.

What is TPO Roofing?

TPO (thermoplastic polyolefin) is one of the fastest growing single-ply commercial roofing systems on the market today. This synthetic rubber material is manufactured combining polypropylene and ethylene-propylene rubber polymers.

The components create an extremely durable, elastic, and UV-resistant roofing membrane. TPO provides excellent protection against ponding water, temperature fluctuations, impact, and weathering.

TPO membrane comes in large sheets up to 50 feet wide to minimize seams during installation. It can be mechanically fastened or fully adhered depending on roofing needs. TPO is installed in white or black sheets with thicknesses from 45 to 80 mils.

White TPO membranes reflect solar radiation, keeping roofs cooler. This helps reduce cooling costs in warm climates. The bright white surface also makes inspecting TPO roofs for issues simple.

What is EPDM Roofing?

EPDM (ethylene propylene diene monomer) is a synthetic rubber roofing material used for low-slope commercial and residential roofs. It has been a popular roofing choice since the 1960s thanks to its flexibility, durability, and ease of installation.

EPDM is manufactured by blending ethylene, propylene, and a small amount of diene monomers with stabilizers. This formula creates a highly elastic, UV-resistant membrane able to handle expansion, contraction, and temperature changes.

EPDM comes in large sheets up to 50 feet wide to minimize seams. It is available in thicknesses from 30 to 90 mils. EPDM is always installed in non-reflective black. It can be mechanically fastened, fully adhered, or ballasted in place with gravel or pavers.

TPO vs EPDM Roofing: Key Differences

While TPO and EPDM share some construction similarities as seamless synthetic rubber roofing materials, they have key differences:

Composition – TPO membranes are a thermoplastic while EPDM is a thermoset rubber. The materials react differently to heat and require different chemical bonding applications.

Seams – TPO sheets are welded together with heat for strong, watertight bonds. EPDM membranes are adhered with contact cement or tape.

Reflectivity – White TPO reflects heat and sunlight while black EPDM absorbs heat. This gives TPO an advantage in energy efficiency.

Cost – EPDM is generally the more affordable option for flat low-slope commercial roofs. TPO has a moderately higher material cost.

Puncture Resistance – TPO offers greater resistance to punctures and tears from impact or walking on the roof.

Ideal Use – TPO is well suited for roofs with rooftop HVAC units or foot traffic. EPDM performs better on simple flat commercial roofs.

What Are the Benefits of TPO Roofing?

Some of the advantages of choosing TPO single-ply membrane for your flat roofing project include:

• Durability – TPO can last over 30 years with proper installation. Thermoplastic material is highly resistant to UV, ozone, and chemical exposure.

• Energy Efficiency – White TPO membranes reflect sunlight instead of absorbing heat, reducing cooling costs.

• Flexibility – TPO remains flexible year-round, adapting to temperature shifts without cracking.

• Puncture Resistance – TPO offers greater puncture and tear strength than other single-ply membranes.

• Weldable Seams – Heated welded seams create strong bonds that won’t separate or leak over time.

• Low Maintenance – Properly installed TPO requires little ongoing maintenance except occasional inspection.

What Are the Benefits of EPDM Roofing?

EPDM also offers a number of performance advantages:

• Affordability – EPDM membrane is the most economical single-ply roofing material.

• Flexibility – EPDM remains flexible and elastic year-round without brittleness or cracking.

• Seam Options – EPDM sheets can be joined with adhesives, tapes, or ballasting allowing design flexibility.

• Easy Repair – Damaged sections of EPDM membrane can easily be patched and bonded.

• UV Resistance – EPDM holds up well over decades of sun exposure. Lighter colors are also available.

• Simple Installation – Large EPDM sheets speed installation. No hot air welding equipment is required.

How Do TPO and EPDM Roofing Compare in Different Climates?

Climate is a major factor when choosing between TPO vs EPDM. Their distinct material properties give each membrane advantages in certain conditions.

TPO is ideal for hot climates like the Southern and Southwestern United States. White TPO membranes reflect heat and lower rooftop temperatures by up to 50°F. This cuts cooling costs and extends the life of the roof itself.

EPDM performs better in cooler northern climates that experience regular freeze/thaw cycles. The thermoset rubber remains flexible to adapt to expansion and contraction caused by temperature swings. Ballasted EPDM systems resist wind uplift in high wind regions.

Both TPO and EPDM stand up well to ponding water, rain, and snow. Their waterproof synthetic rubber construction provides longevity in wet climates prone to algae and mold growth. TPO offers greater resistance to standing water deterioration long-term.

What Are the Downsides of EPDM Roofing?

While a quality EPDM roof can last 25-30 years, it does have some disadvantages compared to TPO:

• Seams are more prone to separation and leaks over time unless ballasted or fully adhered during installation.

• EPDM membranes have less resistance to tears and punctures from impact or foot traffic.

• Black EPDM absorbs heat and provides no energy efficiency benefits.

• EPDM requires the use of adhesives containing VOC solvents during installation.

• EPDM roof repairs are more time consuming compared to hot air welding TPO seams.

What Are the Downsides of TPO Roofing?

TPO has gained popularity for good reason, but potential drawbacks include:

• Higher material costs compared to EPDM. TPO is the more expensive roofing membrane option.

• White TPO can discolor and darken over time, reducing reflectivity and energy efficiency.

• TPO membranes are vulnerable to chemical damage from contact with greases or oils.

• Installing TPO requires specialized heat welding equipment and experienced technicians.

• TPO is prone to shrinking and contraction issues if not allowed to relax before installation.

Is TPO or EPDM the Better Roofing Membrane?

For most climates and roofing needs, TPO is the best single-ply membrane option today. The thermoplastic material offers greater durability, higher reflectivity, and stronger seams. While EPDM remains an affordable, user-friendly choice, TPO outpaces it in longevity and performance.

There are some exceptions where EPDM may be preferable:

• In northern freeze/thaw climates where flexibility is key
• For ballasted flat roofs not subject to regular foot traffic
• When using a white EPDM membrane to gain reflectivity benefits
• On a tight budget when TPO’s higher cost is prohibitive

Work closely with your commercial roofing contractor when deciding between TPO and EPDM. Review the long-term costs vs benefits and how your climate impacts material performance. While advanced TPO formulas are displacing EPDM for many uses, EPDM remains a viable option in the right circumstances.

Key Takeaways on TPO vs EPDM Roofing

• Thermoplastic TPO offers greater durability and flexibility while EPDM provides affordability.
• Seams are stronger with TPO thanks to heat welding but EPDM allows various seam options.
• White TPO delivers energy efficiency by reflecting heat. Black EPDM absorbs sunlight and heat.
• TPO stands up better to foot traffic and puncture damage from rooftop equipment.
• TPO works well in hot climates while EPDM handles cold weather expansion and contraction.
• For most flat roofing projects today, TPO is the best performing and longest-lasting membrane option.

Performing comprehensive roof maintenance inspections, repairs, and leading edge preventative care ensures you get the most out of your TPO or EPDM roofing investment. Contact a qualified commercial roofing company for an assessment of your current roof.

Frequently Asked Questions

Q: What is the difference between TPO and EPDM roofing membranes?

A: TPO and EPDM are two different types of roofing membranes used in flat roof systems. TPO stands for thermoplastic olefin, while EPDM stands for ethylene propylene diene terpolymer. While both are single-ply membrane roofs, they have different compositions and characteristics.

Q: Which one is better for a flat roof?

A: The choice between TPO and EPDM depends on various factors, such as climate, budget, and specific requirements of the roof. TPO roofs are known for their superior seam strength and resistance to punctures compared to EPDM. On the other hand, EPDM has a longer track record and is relatively inexpensive. It is best to consult a roofing contractor to determine which membrane is best for your roof system.

Q: What are the pros and cons of EPDM roofing systems?

A: EPDM roofing systems have several advantages, including high resistance to UV radiation and ozone, flexibility, and ease of installation. However, they are susceptible to punctures and may require more maintenance over time. Additionally, EPDM roofs are typically black, which can contribute to higher heat absorption and energy costs in warmer climates.

Q: How do TPO roofing systems compare to EPDM?

A: TPO roofing systems offer several advantages over EPDM. They have superior seam strength, better resistance to punctures, and can be mechanically attached to the roof surface. TPO is also a thermoplastic material, meaning it can be heat-welded for stronger seams. In terms of energy efficiency, TPO roofs are available in white or reflective options that can help reduce cooling costs.

Q: Can TPO and EPDM be installed on the same roof?

A: It is possible to install both TPO and EPDM membranes on the same roof, although it is not a common practice. Each membrane has its own installation requirements and using them together may complicate the installation process. It is best to consult a roofing professional to determine the most suitable solution for your specific roof system.

Q: How long does TPO roofing last?

A: The lifespan of a TPO roofing system can vary depending on various factors such as climate, installation quality, and maintenance. On average, TPO roofs can last between 15 to 30 years. However, with proper care and regular maintenance, TPO roofs have the potential to last even longer.

Q: Are TPO roofing systems more expensive than EPDM?

A: TPO and EPDM roofing systems have different price points. While TPO roofs may have a higher initial cost than EPDM, their superior durability and energy efficiency can result in long-term cost savings. It is important to consider the overall value and lifespan of the roofing system when comparing costs.

Q: Can TPO or EPDM be coated with a roof coating?

A: Yes, both TPO and EPDM can be coated with roof coatings to provide additional protection and extend their lifespan. Roof coatings can help enhance the membrane’s resistance to UV radiation, improve overall waterproofing, and increase energy efficiency.

Q: What are the differences between TPO and PVC roofs?

A: TPO (thermoplastic olefin) and PVC (polyvinyl chloride) roofs are both single-ply roofing membranes known for their durability and energy efficiency. However, there are some key differences between the two. TPO roofs are typically white or light-colored, offering better reflectivity, while PVC roofs can be black or dark-colored. Additionally, TPO roofs are typically heat-welded for stronger seams, while PVC roofs are usually chemically sealed.

Q: Can TPO roofing be installed on an existing EPDM roof?

A: While it is possible to install TPO roofing over an existing EPDM roof, it is not a common practice. TPO installations usually require a clean, smooth substrate for proper adhesion and installation. It is recommended to consult with a roofing contractor to assess the condition of the existing EPDM roof and determine if a TPO installation is feasible.

If you need help making the right choice on replacing your flat roof in Maryland or NOVA, give us a call! We would love to come out and take a look at your roof and help you come up with a plan that is right for you.

We have vast experience in Commercial and Residential Roofing and we would love to share our expertise with you.