TPO vs EPDM Rubber Roofing – Flat Roof Guide

Are you looking for a quality, energy efficient solution for a low slope roof and are not sure whether to go for a TPO or an EPDM rubber roofing membrane? It can be difficult to distinguish between the two products, as both are single ply roofing membranes.

However, there are important differences that you need to be aware of to figure out which roofing membrane is right for you. When making your decision, consider such factors as cost, longevity, durability, maintenance, ease of installation and energy efficiency.

To learn more information about how TPO and EPDM stack up against one another, refer to our comparative guide.


Estimated 1500 s.f. Flat Roof Costs in US Average Flat Roof Costs in US
Rubber Roof
Rubber
$7065
TPO Roof
TPO
$7455
PVC Roof
PVC
$8055

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Cost

EPDM roofs are the most economical choice for single ply roofing membranes. TPO roofing membranes are more expensive than EPDM. Regardless of which membrane you choose, it is better to spend more money and invest into a thicker membrane. Both EPDM and TPO roofs perform better and last longer if they are thicker.

Longevity

By far the most important aspect that will determine the longevity of a single ply roofing membrane is the method by which the overlapping seams have been attached together. Permanently attached seams are the safest solution, and improper attachment can be the cause of 99% of leaks.

It is difficult to determine the longevity of TPO roofing membranes for a couple of reasons. First, this is a fairly new roofing product, there are no TPO membranes in the US today that are older than 15 years. Second, TPO membranes continue to be an experimental products- they are all in their 2nd, 3rd and in some cases 4th generation of formulations, so it is not possible to definitively say how low any of these will last. Moreover, many TPO products have been pulled off the market in the past both for seam and material failures.

Durability

An EPDM roof has a solid reputation for durability. Made of rubber compound, EPDM roofs have been on the market for decades- having properly tapered seams and detailed flashings, an EPDM roof will last up to 25 years. It is recognized in the industry as a dependable roofing material that offers resistance against ultraviolet light, ozone, oxidants and severe weather conditions. An EPDM membrane will also preform better than TPO in colder climates.



TPO seam strength is 3 to 4 times that of EPDM adhesive and tape seams.TPO membranes are manufactured to be as durable as EPDM. However, because there are continuous changes and improvements to the formulation, different TPO membranes perform differently. TPO is known to respond poorly to ponding water (it splits and cracks) and also does not have strong resistance to heat and solar overload.

Maintenance

In the beginning of its service life, a properly installed EPDM membrane will not require much maintenance. However, unlike TPO ( which has hot-air welded seams) an EPDM’s seams are treated with an adhesive, making them ultimately vulnerable to coming apart. This means that in the long run an EPDM roof will require maintenance to keep in tact. Be aware that EPDM responds very poorly to any kind of solvents and oils. Therefore, you should not use cleaners or conditioners that contain petroleum solvents, harsh abrasives or Citric based cleaners as these may cause irreparable damage to an EPDM membrane.

TPO membranes are not as easy to maintain as EPDM roofing membranes. In general, it is problematic to weld new materials to a TPO membrane, because as compounds age they lose their pliability and their subsequent thermoplastic capabilities. Consequently, to effectively heat weld new material to an old membrane may require an an “activator” similar to hypalon to seal repairs.

Ease of Installation

An EPDM rubber roof is easier and faster to install than a TPO roofing membrane. EPDM requires no special equipment for installation while TPO needs to be hot air welded. This makes installing a TPO roofing membrane a more complex and costly process that also requires specialized knowledge. While a beginner roofing contractor will most likely be able to properly install an EPDM membrane, you should only hire an experienced contractor to install a TPO roof. Improper installation will invariably cause leaks and will require costly repairs or replacement.

Energy Efficiency

TPO membranes have become an increasingly popular single ply roofing choice because they offer energy efficiency. White TPO membranes are considered to be a “cool” roofing technology, but other colors of TPO are also formulated to have sun reflective properties. With a TPO roof, it is possible to save money on cooling costs of both residential and commercial properties. By reflecting solar heat, a TPO roof is able to maintain a cooler thermal balance inside the space, reducing the need for additional air conditioning. Energy efficiency makes TPO roofs particularly popular in hot sunny regions that get a lot of cooling days.

While EPDM roofing membranes are also available in white and will offer better reflective properties than darker colored EPDM, an EPDM roof will not offer the same level of energy and financial savings as a TPO roof.


Estimated 1500 s.f. Flat Roof Costs in US Average Flat Roof Costs in US
Rubber Roof
Rubber
$7065
TPO Roof
TPO
$7455
PVC Roof
PVC
$8055

See costs in your area Start Here - Enter Your Zip Code




Published date: September 24, 2012

6 thoughts on “TPO vs EPDM Rubber Roofing – Flat Roof Guide

  1. maria

    Would TPO be recommendable for roof with a 1:12 slope? would TPO ribs look good on the sloped roof? This is for a residential apartment project in Oxnard CA, very close to the ocean with temperatures from 47F to 74F, rarely below 40F or above 81F

    Reply
    1. TPO Roofer

      Maria,

      TPO should have now problem with 1:12 roof pitch.

      With that low of a pitch/slope, the ribs will be barely visible, if at all, unless your complex can be seen from hills above.

      I’d say ribs are a waste of money. What I’d recommend IF the roof is visible, is to go with something like beige/light grey color and no ribs. White would be too bright, and with temps rarely above 81F the grey/beige roof is cool enough, to reflect most of the sun.

      Good luck.

      Reply
  2. BOB

    LENNY, I HAVE ANY OLDER 5TH WHEEL TRAVEL TRAILER THAT I NEED TO PUT A NEW “RUBBER ROOF” ON. I HAVE READ COMMENTS ON TPO AND EPDM MATERIALS. I HAVE DONE ALL OF OUR NEEDED REPAIRS MYSELF (WATER HEATER, FURNACE, PROPANE PIPING, AND ROOFING (METAL) REPAIRS TO OUR BUILDINGS. I KNOW I CAN DO THIS, ‘IF”, I HAVE THE RIGHT MATERIAL FOR THE JOB. I BELIEVE THIS BEST MATERIAL FOR THIS APPLICATION IS THE EPDM. AM I RIGHT? THANK YOU, BOB

    Reply
  3. Never Leak RV Roofing

    If you have to replace your RV Roof go with EPDM Rubber Roofing, if its worn out we install our Safe-T-Plex 20 Year RV Roof Coating…

    Reply
  4. Liquid Rubber

    TPO is higher quality with the welded seams and all, but EPDM works just fine as well. I’ve worked with lots and lots of EPDM roofs. and if i’m doing a green roof, the membrane will almost certainly be EPDM, all day long. but, as rusty notes, both are very similar.

    Reply

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