TPO Roofing Overview

In recent years there has been a growing demand both in residential and commercial construction for more energy efficient roofing systems to help reduce costs as well as the negative impact on our environment. One of the products that has been able to meet the demand as a result has become increasingly popular is TPO roofing systems. TPO or thermoplastic polyolefin single-ply roofing membranes are known for their heat reflective properties as well as their ability to resist damaging ultraviolet, ozone and chemical exposure. In addition to this, TPO roofs also provide a number of other performance and installation advantages.


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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TPO-based products have been successively utilized in many applications and industries, including the automobile industry since the 1980s. In 1989, the first TPO-based membrane was used in the roofing industry as a non-reinforced sheet and in 1993, an improvement was made where the original non-reinforced TPO membrane was replaced by a membrane that contained reinforcing fabric. Ever since then the TPO roofing market has grown to hundreds of millions of square feet annually and continues to expand. Today, TPO roofing membrane is the fastest growing segment of the U.S. single-ply roofing industry.

How is a TPO roofing system manufactured?

TPO membranes are made from ethylene propylene rubber and a number of filler materials, such as talc, carbon filler or fiberglass. Rubber, Ethylene ( an organic gaseous substance) and propylene (a byproduct of petroleum refining) are all polymerized (bonded together by chemical reaction) using special technology. Afterwards, filler materials are added to reinforce the membrane’s strength and durability for optimal construction use.

TPO roofs are specifically designed to be an improvement over EPDM roofing membranes, by combining the durability of EPDM rubber with the exceptional performance of hot-air weldable seams. As a result, TPO’s seam strengths are 3-4 times greater than ones on an EPDM rubber roof’s adhesive and tape seams. TPO roofing systems are manufactured in white, light gray, and black colors. There are two thicknesses options available: either 45 mils (.045″) or 60 mils (.060″). TPO membrane’s width and length varies depending on the manufacturer but you can expect a a typical TPO roof to be six to six-and-a-half feet wide and one-hundred feet long.

What is the process of installation?



There are three different methods to installing a TPO roofing system. A TPO roof can be installed fully-adhered, mechanically-attached or ballasted. When the TPO roof is fully adhered it means that the membrane was glued to the substrate using a special strong adhesive that creates a chemical bond with the TPO. When the roof is mechanically attached, it means that a special screw-type fastener is utilized to attach the roof to the substrate. Note that the type of fastener used will depend on the type of substrate you have. In this process, adjoining sheets of TPO membrane are overlapped, covering the fasteners and plates, and joined together with a minimum 40 mm (1 1/2 in.) wide hot air weld. Lastly, when the TPO membrane is ballasted, it means that it is laid over the top of the roof, carefully sealed all around the perimeter and at all penetrations and then a ballast is put on top of the membrane to hold it in place. Ballast typically consists of smooth, round, river rock 2″ – 3″ in diameter. The rock is applied at a rate of 1,000 to 1,200 pounds per roof square (100 sq. ft.). It is also possible to use concrete pavers instead, which average 20 pounds per square foot.

What are the performance advantages of TPO roofs?

A TPO membrane is highly flexible and durable, possessing strong resistance to tears, punctures and impact damage. Moreover, the membrane’s flexibility allows for building’s movement and setting, without compromising the roof’s performance. It is important to invest into a thicker TPO membrane because thickness results in better weathering resistance, and protection against solar UV. A TPO roof is also algae resistant and stand up well to exposure from ozone and sun’s ultraviolet rays. A residential home or a commercial building can save a lot of money on energy costs by installing a white color TPO roof, because the white color will reflect the ultraviolet rays of the sun, keeping the space inside cooler. This also greatly helps the environment by reducing the “heat island effect”. To make sure that the TPO roof membrane you are planning to purchase has the appropriate cool roof properties, be sure to insist that the TPO installed on your home or building meets the initial and three-year ENERGY STAR requirements. Another factor that makes TPO roofing membrane a green product is the fact that TPO polymer does not contain chlorine and there are no chlorine-containing ingredients added during production.


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



How durable is a TPO roof?

Keep in mind that TPO technology is fairly new, it is only about 20 years old. As a result, the chemical composition of the membrane continues to change and be improved on to achieve greater durability and longevity. At this point, manufacturers offer 10, 15 and 20 year warranties on TPO roofing systems. You need to be cautious when purchasing a TPO roofing membrane since they are not all created equal. Because currently there is a hot growing market of TPO, a lot of manufacturers have recently started producing and offering their own TPO membranes. However, not all formulations work equally well, and it is in your best interest to purchase a TPO roof from a manufacturer who has been producing these membranes since their inception, another words, for at least 20 years.

Can A TPO roofing membrane be recycled?

One of the biggest advantages of the TPO membrane in a market that demands green building materials is that it is 100% recyclable. During production process itself, the membrane can be ground into “rework” and this ground up material can once again be incorporated into the bottom ply during the extrusion process to produce a brand new TPO roofing membrane.

Related TPO articles:

Pros and Cons of TPO Roofing.

Installation Guidelines for TPO Roofing.

TPO Long Term Performance


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



18 thoughts on “TPO Roofing Overview

  1. Greg

    I have a roofer on a commercial project that is suggesting a self-adhered TPO roof in lieu of the glued TPO roof. The manufacturer is the same and the warranty is the same, but didn’t know if there are advantages or disadvantages to self-adhered versus glued.
    thoughts?

    Reply
    1. Leo - Roofer

      Greg – self adhered has glue already applied to it – like a sticky tape… but i’m sure you already know that. I don’t see any benefit one way or another … If anything, in my opinion glued is better, because you don’t run in situations where you need to cut a roll, and weld seams, but there is glue applied to underside of the membrane – this makes welding impossible, as glue is in the way.

      What’s wrong with current TPO roof? Why does it need to be replaced?

      Most TPO/PVC roofs should be repairable (PVC much more so, because they are cross-compatible with each other, over decades).

      Basically I think unless your current roof is cracking everywhere and seams are all coming apart – just repair old roof, and keep it for another 5-10 years… hopefully it will last that long.
      Good luck

      Reply
  2. Lee

    We had some idiots install a tpo roof. Long story short they were clueless. 0 slope. Standing water. Seems glued. Flanges not adhering & so on. Question is can you glue seems like you do epdm or do they have to be hot air welded? Is there a certain caulk you can use? We refuse to pay them & have to do some self repairs. Thanks.

    Reply
    1. TPO Roofer Post author

      Lee – great question.

      In theory, you should ONLY heat weld seams. That was the whole point of TPO roofs – make a cheaper version of PVC with all the benefits (heat welded seams).
      But because many generations of TPO had failing seams (and other problems), and may be incompatible with each other, especially when you consider there are over 10 manufacturers of TPO, each with many faulty reincarnations – TPO industry came up with a band-aid in form of glued seams.

      So you basically have an overpriced Rubber with many other problems, and still glued seams 🙁

      So to answer you – yes you can glue TPO seams… but primer and seam tapes must be compatible (at least same brand as the sheet itself). Also there should be 2-3″ splice tape (thin tape that goes in between two layers of of TPO membrane..
      Also you should have seam cover tape installed over seams …

      IF the roof is leaking – don’t pay the contractor. IF contract specified WELDED SEAMS – don’t pay. If contract called for glued seams and roof does not leak – you kind of should pay the roofer…

      While ideally they should have welded seams, manufacturers allow and accept glued seams.

      As for “certain caulk” … yes there should be… white caulk for TPO … but just so u know these are useless and fail after 1-2 years, and only create more problems than they solve… I would not use caulk on seams!

      Best of luck … let me know how it goes … maybe send a few pictures of your roof

      Reply
  3. Brandon

    Where can I find more information about recommended installation methods over an exiting asphalt or tar roofing?

    Reply
  4. kevin

    Hi – can you tell me if TPO is mechanically fastened to a concrete roof, can it be easily removed at a later date. And if it can, am I correct in reading that it can then be recycled into new TPO.

    thx.

    Reply
    1. leva

      Hi Kevin,

      TPO is not installed directly over concrete deck, but rather, rigid insulation is either glued or fastened to the concrete, and then TPO (or PVC or EPDM rubber) i fully adhered over insulation.

      So, no it cannot be easily removed.

      I’m also not familiar with TPO roof recycling. I do know that PVC roof can be recycled.

      Reply
    1. leva

      @ Craig

      I don’t believe so – TPO can catch on fire, so I would not use it on top of chimney cap. Why not use stainless steel?

      Reply
  5. Houston Roofers

    TPO is a great product. I didn’t believe in it at all but once I saw that it withstood the damaging affects of Hurricane Ike in 2005 I was a sure believer. I’ve been pushing it ever since. As stated above, it’s not made for foot traffic but if foot traffic is a must, go with traffic strips.

    Reply
    1. leva

      @ Houston Roofers – Any roof in hurricane zone must withstand winds of upto 110 mph.

      Flat roofs installation allows great flexibility, and special precaution are taken to increase wind uplift rating, such as use of perimeter half-rolls, and extra fasteners, etc. This applies to not just TPO, but also to PVC and other single ply membranes.

      Reply
  6. Ken Cavanaugh

    Can you please tell me if TPO can withstand rooftop furniture? Would I have to build a platform for furniture and if so what do you recommend?

    Reply
    1. leva

      Hi Ken,

      Answer is no – TPO is not made for being used as roof deck or for regular foot traffic – it will immediately void your warranty.

      You might wanna check out IB DeckSheild – a PVC membrane made for use as roof deck, with foot traffic and furniture, etc.

      Reply
      1. Christina

        Another WONDERFUL company to check out is Duradek. I work for a roofing company, and this is a company that we work closely with for installing walkable waterproofing membranes. Their prices are pretty middle of the road, but they offer a great warranty and really take care of their customers. Plus, the finished product looks fantastic!

        Reply
    1. TPO Roofer Post author

      Caltop,

      Materials are usually 10% waste/seams so figure 12100 s.f of material.

      I’ve never seen a 19-r insulation board. ISO is 6-r per inch, so 6-r/12-r/18-r for 1/2/3 inch board. 3.3″ board gives you 20-r.

      Cost for insulation:

      Cheapest I get is $30.72 for a 3″ 4×8′ board (18-r). So on 110 squares about you will need about 350 boards @ $10564. However, for roof that big, you should get about 10-15% discount.

      Single ply prices vary greatly between brands, thicknesses and suppliers, and can be $0.50 to $1.00 per square foot. Also flashing, drip edge, drains – can’t really guess here.

      Labor – once again varies, but about $150-200/square for installation.

      Good luck

      Reply

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