Single-ply Flat Roofing Systems: PVC and TPO




From The Editor: – this post has 40+ VERY interesting comments from “both sides of the isle” so to speak. We highly recommend you read these comments, after the post.

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If you are a building owner, facility manager or even a homeowner with a flat roof that leaks, and you are interested in or got a bid from a contractor to install a new flat roofing system called TPO (Thermo-plastic olefin), this is a must-read article for you, because you will not find this information anywhere else.

Foreword: TPO is a hot-air welded thermo-plastic single-ply roofing membrane produced by numerous manufacturers. TPO was created to be better than EPDM Rubber roofing and cheaper than PVC roofs, while it would still provide all the benefits of hot-air welded seams. It was a good plan, and now TPO membrane covers billions of square feet of roofs and represents a multi-billion dollar roofing market, but there are some problems…

In it’s fairly short life (about 15-16 years) TPO went through at least 2 generations. 1st generation of TPO roofs began to fail in the late 1990′s and early 2000′s. Now, some manufacturers are on their 3rd generation (or major reformulation) of their TPO products. At the same time, TPO’s main rival – PVC roofing membrane such as IB Flat Roof, has not changed its formula in over 30 years.



The video clip above below a brand new TPO roof burning on a roof of a new office building that was built in Salt Lake City, and filmed by the Fireman crew.

Why you should not get a TPO roof – TPO roof on fire video



Whether you are a customer looking for a new flat roof or a roofing contractor, I recommend that you to do some serious research on TPO before investing in it. This will serve your own benefit.

To start, you may want to check out the WSRCA (Western States Roofing Contractors Association)  “TPO roof study” – http://www.wsrca.com/bookstore/index.htm.

WSRCA’s test roofs in Las Vegas, NV, Anchorage, AK, San Antonio, TX, and Seattle, WA demonstrate the product service life in diverse climates throughout the western United States. All have weathered past the four year mark, and the results are now published.



The problem is that for some reason they pulled off 2007, there is still no 2008 edition and only a 2 year old report from 2006 is available. But here is the “rumor” from trusted sources:

TPO roofs in the above study lose minimum of 1 mil of thickness per year and some TPOs lose as much as two mil per year (in 10 years that will be 20 mil – imagine that on a 45 mil membrane). The average top ply thickness is 15 mil – some are 12. Once you are down to the scrim, the roof is gone, and the UV will eat the scrim and bottom ply.





Also, there are problems with seam failures, premature curing, cracks along the seams, etc. These are TPOs made in 2001-2002 (second generation) Supposedly there is no 3rd gen. going into production, and I suspect that the reason for the 2007/2008 edition of this book not being available is because manufacturers pressured WSRCA to pull those off. I could swear that I saw an ’07 edition available on sale in January ’09, and now its not even listed.



Aside from the above, most TPOs and maybe some PVCs (to cut costs) come with a wicking scrim, so you need to do something about the edge of the weld – that is like welding twice, and there is still lots of room for error, and once the water gets to the scrim, it will delaminate the membrane… I don’t need to explain the consequences.

So, the bottom line – do you want your customers to have a 2nd/3rd gen. of repeatedly failing roof technology and put your reputation on the line for a gimmick created by greedy roofing manufacturers, who are looking for ways to reduce costs at the expense of quality (putting cheap fillers into membrane to create nominal thickness)? What is the difference between 45 and 60 mil TPO if weathering surface is 12-15 mil? Just a thicker bottom play that is made of junk in a first place.



Another thing that amazes me about TPO is the peel-n-stick seams. WHY?… The whole point of thermoplastic roofs (PVC & TPO) is the hot-air welded seam… EPDM rubber roof can be peel and stick… but TPO? All it does, is attract hacks into thermoplastic roofing market. Those who do not care about quality install, fly-by-night dudes, etc. I mean, if you as a roofing contractor go and spend $10-20K on the hot-air welding equipment you probably won’t disappear tomorrow, as you need to pay for that equipment and make some money on top of that. You as a roofing contractor are probably in it for the long run…

Instead of conclusion:

As I mentioned in the beginning of this article, the idea of a TPO roof is great. A cheap, naturally cool, long lasting flat roof system featuring hot-air welded seams is something of an ideal for the roofing industry to strive toward. However, the “cheap” part in TPO is why all these roof failures occurred, and will be happening on a wide scale in the near future. TPO’s problem is not the faulty design. In Europe, TPO has been around for decades and is considered to be a very good flat roofing system.

However, here in the US, roofing manufacturers put the bottom line in their accounting books above product quality and interest of their clients by manufacturing their TPO membrane using primarily cheap fillers and low quality wicking scrim, without proper testing or acquiring UL certifications. In the end, roof owners and to some degree roofing contractors become victims of corporate greed and irresponsible business practices.[PSGallery=1ondfvgxk]

52 thoughts on “Single-ply Flat Roofing Systems: PVC and TPO

  1. In Florida, I have practiced Roof Consulting for 21 years. I avoided the ill fated original single ply debacle with Hypalon, the CSPE vs. CPE, the 200 permutations of black EPDM seaming, and was reluctant to get into white single plys. Back door approach with clients insisting on TPO forced me to take another look. I simply am old school with total of 35 years experience overall, and do not like the idea of a single ply. Lately, every client thinks TPO is the greatest things since pockets on a shirt. I have very little bad I can say until this article. I only hope that my hesitation was partly due to my diligence in researching the facts, but I still have millions of s.f. of the crap down.

    What are we to tell clients about this stuff? What can be done? Is it any one manufacturer? Is anything being done at the mfg level to fix this as far as you know?

    Quite disconcerting information.
    I would like to be placed on your update list for this and similar topics, can you do that please?

    Thanks for being brave and candid. There are not enough people out there to tell the king he has no clothes.

    Rich Allen

    1. Hi Rich,

      I’ll try to figure out how you can follow the this article and comments.

      As far what you should tell your customers – I think article is self explanatory – stay away from TPO. What manufacturers are doing is: My own opinion based on the industry gossip) – they try to threaten WSRCA and I believe the reason for 07/08 reports not being available is because of massive membrane failures across the board.

      Think about it – Manufacturers now have billions of sq. ft. of 2nd/3rd gen. TPO on the roofs across US, and they want to handle material failures quietly. They definitely don’t want WSRCA or NRCA telling roofing contractors and building owners that TPO sucks. They quietly release new batches of membrane, hoping “this one will work”.

      Don’t forget that First Gen. TPO’s were pulled off in late 90′ and early 2000′s, and since there are so many different types and brands, no one knows what exactly they are getting.

      I am not sure about Hypalon, but the only PVC roof failures of any significance that I know of, where those of Trocal, about 20 years ago. Bear in mind that that was a Non-Reinforced PVC that would shutter like glass in a very cold weather, if stepped on. The only reason it was produced, was at the request of US Military for it to be non-reinforced. That product in of course no longer made, Trocal was bought out by Sika (as well as Sarnifil) and I have not heard of any other PVC problems.

      It is funny how roofing experts always bring that Trocal incident as about the only bad thing about PVC’s performance on the roof.

      Anyway, back to TPO: whether its problems are attributed to just one MFG – I don’t know but apparently most of them are problematic and some are just worse than others. Even if I knew any particular MFG, I could not name them for obvious reasons.

      If I get more good info, I’ll post it here.

      Leo

  2. Thanks, I appreciate that.
    I have been lucky, Florida usually gets everything first. Or no worse than second behind California.
    We have failures on a LOT of stuff before others see it due to intense heat and UV.

    Do you know of, or have experience with the ELMS material that is soybean based?
    I need to drive this one out of the woods with some better news than I have so far.
    Any rumors on that would be appreciated.

    I worked for Tremco for first 15 of my 35 years, and not all in sales.

    Some of the experience was handling failure claims.
    I could write a book on what a joke that this matter became internally on how to avoid paying, and even avoid answering the requests for help.

    Tremco inherited the BF Goodrich Hypalon system in 1979 and it was a complete mess, not to mention the product was 20 mils thick with a 15 mil (…….drum roll) asbestos backer. Whoooeee. Did that one go over well.

    Some scary “chit” in this biz.

    I also had a PVC blow-out years ago *in ST. PETERSBURG, FLORIDA no less, shattered on a hospital roof over their sterile stores, and pharmacy area. That was like a cannon ball dropping on a plate glass. 3″ up to 6+inches of stress relief from the center of the spider web out. People in the hospital were panicked cause they thought from the awful noise that something terrible had happened. *Well, it did.

  3. I have recently seen several mechanically attached, reinforced Trocal roofs ruined by approximately 1/2 inch hail. All were reported to be 10 – 14 years old.

  4. I have heard from a reliable source that United coatings is developing acrylic coatings with reinforcement at the request of TPO manufacturers (carlisle among others) to head off the quickly coming flood of tpo failures. It appears that this new generation of TPO has as many problems as generations past and they are stress cracking in the hot desert climates at all the welds and accessory boots around pipes and drains and curbs.
    I always wondered how these manufacturers could (back in the 80′s) offer a ten year system warranty that only lasted 5 years, re formulate and offer another 10 years which only lasted 6, then come back and offer 20 years when they have never hit 10 yet. Only a roofer would fall for that trick 3 times.

  5. Great work!

    You couldn’t have said it any better. TPO is garbage and you were dead on with the use of it in Europe. The differences in the European sheets and the “commodity” sheets here in the US are night and day. The TPO roofs in Europe actually cost MORE than PVC.
    The likes of the big guys in Firestone and Carlisle are the ones pushing this junk into the marketplace to boost their profits. Check out some documents referring to lawsuits by both Target and Walmart against Carlisle for their faulty TPO roofs. You won’t hear about that in the mainstream as they’ll do anything to keep it quiet but, call on Walmart or Target and see what they’re using now because, it definitely isn’t TPO.
    There are FOUR manufacturers of TPO right now in the US and close to 16 sellers. ASTM can’t even keep up with the formulations anymore and have a very hard time trying to standardize it.
    Lets also mention the fact that these roofs light up like christmas trees when exposed to fire. There was a huge fire in Salt Lake City recently on a TPO roof that went up in 3 minutes.

    http://www.youtube.com/watch?v=ND7U2U1gIYA

    This stuff is going to be a huge headache in a few years and already has been for many business owners. Carlisle just came out with a “new” system and slammed other TPO’s for failing prematurely how about that! They had to incorporate a new coating to make up for it’s inability to combat UV degredation thereby, admitting that they’ve been making a faulty product for 15 years.
    Their EPDM sheets have worked well for them and they use that success to push this junk into the market and that is too bad because, architects TRUST their input. It’ll end up biting them in the butt eventually and companies like IB and every other PVC manufacturer will continue to get calls from business owners to replace failed 4-6 year old TPO roofs that the General Contractors VE’d onto the job originally and the architect specified or may not have even specified due to the misinformation for the manufacturers reps.

    Here’s another interting article for MRCA and NRCA regarding TPO and EPDM actually failing fire tests.

    http://www.mrca.org/files/public/MRCA_NRCA–Fire_testing_of_membrane_roof_systems.pdf

    Let’s stop putting this junk on roofs. PLEASE

  6. Leo,

    You said it well when you mentioned that the TPO manufacturers are quietly releasing new formulations into the market. Since you can’t name manufacturers by name for liability reasons understandably, allow me to.

    If you folks weren’t aware, Carlise recently released a new piece on their Octaguard formula and in their marketing piece go onto show the many failures with TPO sheets. I find it hilarious how they fail to mention their own failures but, I digress. Anyways, in talking to roofing contractors Carlisle released the press memo in October but, the roofers were told by Carlisle that the Octoguard product has been being sold to them since early in the year. Now that is absolutely outlandish and only further reason for Architects and Consultants to STOP specifying TPO. You don’t know what is being manufactured and the formulations are too inconsistent to rely on them.

    Single-ply membranes that are meant to be hot-welded at the seams are a fickle thing. The membrane’s chemical make-up must be similar enough to allow for the 2 sheets to weld to one another. If these TPO sheets are constantly changing how are you ever supposed to repair a hole or tear in a membrane when they aren’t the same? It’s reality and it happens all of the time. Talk to any roofing contractor who installs materials other than TPO, a reputable contractor, and they will let you know that they don’t like working with the stuff. It’s too stiff and not pliable enough to work with, it’s very hard to know when you get a good weld on the seam, the have to caulk any cut seams since they are made with cheap wicking scrims, and they don’t repair well at all since the new membranes are not compatible with sheets only 2-3 years old!! Not to mention that they are starting to show signs of failing in as little as 4-6 years when they are promised to last 20. Sure the contractor can blame it on the manufacturer and the product but, at the end of the day, the owner is looking at you like you’re a nit-wit and should’ve known that this product was going to fail and you let them put it on their roof. After all, you’re the expert Mr. Contractor/Consultant/Architect.
    The more Consultants I talk to, the more they are staying away from TPO for all of these reasons. I just wish the Architectural community would smarten up and realize this as well although I don’t expect them to since they really aren’t worried about the roof on their projects and usually just pull in a Consultant to help with the roofing specs.

  7. I am not surprised at anything any longer. After 36 years in the roofing biz, the problems keep coming, and the supposed solutions or alternatives are not far behind.

    If you were tending towards conspiracy theories, you may think someone (in the new world ROOFING order) was scheming to keep the failures spaced out evenly so there is a constant demand for roof replacement of failed product with the next best thing.

    So, everyone is repeating mistakes. How do we as specifiers avoid this pitfall, and is it reasonable to assume that a client with even half a brain is going to accept a hold harmless clause due to material selection (some may call that design), and what can we do to avoid the pending litigation?

    In most cases, frankly the client has asked for the TPO, rather than my alternative (and obviously more expensive choice), and in some cases I have alienated clients because of my steadfast insistence on putting a quality specification out to bid. Invariably some hot shot wanting to make a name for himself at the company HQ hears about TPO or reads about it in the Airline’s seat back magazine and hears that it is a green roof, cost less, reflects sunlight so there is an energy rebate from the local utility, etc. ad naseum. How Can you fight city hall? I get my teeth kicked in regularly on most of these points, and then have to roll over a play dead like a possum in the road waiting to become the road kill of this client’s future liability.

    Does anyone feel that a “warning” to the client with backup fact sheets would be too alarming?

    At least this would make THEM aware, that WE are aware, that the MANUFACTURER’S are aware of inherent problems in the TPO formulations, and that these roofs could be fire hazards, and a very high propensity for premature failure is likely, and this propensity increases over time in its potential rate of failure as it ages, dries out, becomes brittle, shows signs of “welding” failures, wicking of the scrim, and a knowingly poor choice for scrim byt he Manufacturer’s inasmuch as there are higher priced materials that could have avoided this type failure.

    Keep up the dialog, I am getting to the point since I will be 64 in less than 2 months, maybe retirement is looking pretty good all of a sudden.

    Does anyone feel this is a repeat of the history of EPDM in the first 20-25 years where the seaming changed every few months? Loaded up with Lamp-black as filler and was the disappearing roof at better than 2 mils lost per year? Especially in Florida. But wait. These roofs have manufacturer’s warrantees. That won’t be a problem. Besides, it is much less expensive than that old smelly BUR.

    Good luck with that one.

  8. Our company has been applying TPO since 12 years. We have warranted jobs on all mayor construction on the island of Curacao and Aruba Dutch Caribbean. Airport terminals Hotels Offices etc. There has been not one case where a call has been made on the warranty as yet. As far as the membrane itself after 10-12 years looks great ad warranty will be extended for another period of 5-10 years. The amount f sun (thus UV) is very high in our climate. All clients agree on the “thermal” value (reflectivity) of the white membrane which results in their electricity bills.

    This article begins with the following statement…..”this a must-read article for you, because you will not find this information anywhere else.” I WONDER WHY??

  9. Do you remember the words Phenolic, Hypalon, PUF, Neoprene, syn slate, IRMA, Insulation delamination, non-reinforced PVC, PIB, APP, to name a few, just read 1985 Second International Symposium on Roofing technology. TPO will be a new word.

  10. In this reasonably long diatribe, check out the number of times I use the word COST, and it’s permutations.

    In my total career, starting in late 1974 I have been collecting data on roofing, magazine articles, reprints, manufacturer’s literature, and best of all – Manufacturer’s Catalogs (more recently, their CD Roms).
    I have well over 100 catalogs, and the number of products and manufacturers who are no longer around, not just merged, which is another category, but their disappearance, along with their failed products is mind boggling. Bill said it well, there are so many products that we remember that have not worked, it would be a week long seminar just to discuss each one and what happened.

    Not just the products themselves, but the “ingredients” used have been interesting as well.

    I’m sure everyone remembers asbestos and how that worked out. Fact is, while asbestos was a major health issue to many who worked around the friable or free and airborne variety, at NO TIME, on any tear-off roofs did asbestos become substantially airborne to exceed the limitations set and tested on the jobsites. Even when back-pack blowers were used, and tear off machines. Lots of dust, but none that exceeded the minimum permissible levels for health concerns.

    So, a good product ingredient was banned, mostly because of the manufacturing side of handling the products in the factory, the threat of litigation, and the industry knee jerk reaction to the “possibility” of someone having problems. The reformulation resulted in higher costs.

    I know of no direct correlation of asbestos harming any roofer. If I am wrong, I would like to be proven wrong so I can 1.) apologize for my ignorance, and 2.) become aware of why very few people to this day can name a single incident where asbestos was the cause of problems with people’s health working in the roofing contracting industry.

    The next big issue of ingredients is of course the California standards for VOC’s. This forced every company to reformulate their products to eliminate the VOC content from their materials almost overnight, (virtually in the historic time line of roofing, it seemed like it). If there was an alternative that was just as acceptable, just as inexpensive, and just as proven, why did it take legislation to change everything? The obvious answer is cost.

    And, because the substitutes (at least at that time), were NOT equal. I am not certain that today they are equal to the formulations that many of us were accustomed to. Health issues again, directly with workers in the contracting industry have not been well documented, if there have been any problems. Maybe long term it could be proven, but the information on this is virtually non-existent.

    The manufacturers of roofing products in North America have had various spurts of growth attributed to product permutations, the economy at various times, and the “natural selection process” that economies of scale forced smaller companies to try and compete, unsuccessfully, forcing the retraction, then cyclic re-entry of others. Overall, however, there has been only marginal growth in sheer numbers of “major manufacturers”. Does anyone think there could be any discussion among the big boys about products, trends, and raw materials? Of course not, that is Anti-trust, and no one would dare risk the wrath of the government for profit gains. Silly me for thinking this.

    When years ago crude oil was a reasonable constant in origin of supply, vs. the current state of “mixed” supply or blending, the output of roofing materials was much more predictable, and constant in quality.
    Today, when various crude sources must be blended, the fact is regardless of the quality control aspects in the labs of these manufacturers, the products have subtle differences chemically from batch to batch. There are only so many variables that can be accounted for in testing due to the technological expertise, and more importantly, the cost of doing finite testing on each source of raw product.

    When you put these issues in perspective, we have continually changed all product formulations in every petroleum based material for the last 25-30 or more years. Regularly. So, how does every product remain the same? It doesn’t. Too Costly.

    East of the Rockies, currently, most major crude oil supplies used for roofing relies virtually entirely on crude (and Flux) coming from Venezuela. What plans do you suppose are being made to have a back-up source for these supplies if Chavez decides to cut off trade with North America? Or raise prices to become prohibitive. Will we see another round of raw material changes that will subtly affect the entire product lines using this new source?

    With Modified Asphalt membranes, we are already experiencing the modifiers having moved from scrap APP literally dug up from landfills before sufficient quantities of these modifiers could be produced. Quality? Who knows? Cost, of course, was very low.

    We have seen the variations of SBS suppliers who have used Kraton Rubber crumb finding less expensive alternatives, and the cheapening of prices by varying the quantity of rubber in the manufacturing by changing formulations. To reduce Costs.

    And there are so many things we are NOT being told about the actual sourcing of materials it can be a real crap shoot. While the in-house testing, Independent testing, UL, FM, ad nauseum all rely on the product PERFORMANCE, not the formulations, this does not imply quality of materials in-situ after aging will pass the same tests.

    What happens later is not something anyone wishes to discuss. Aging in the lab using instruments and controlled calibration can often “predict”, but can not simulate what is being actually done to a product in the field.

    All of this commentary is meant to offer food for continued thought that the end product may in fact be something that has not worked well, and has seen many failures, re-birth, re-formulation, and often major changes, but the continuum is that every manufacturer, of every product, has not been totally truthful (not that they are required to), but have played footloose with the consumers by insisting in marketing their materials that “we have not had a problem”, with product (fill in the blank). That is ludicrous and we all know it. There is no product that is immune from product problems.

    The manufacturers have too much at risk to admit anything. Too Costly. Their issues if exposed would be corporate suicide. They vigorously defend anything that could be a threat to their product being exposed, and will buy their way out of situations vs. going to the mat with the defense of their product because they know it cannot be done.

    The cost of failure, and the cost of litigation, loss of revenues, loss of credibility, and obviously loss of stock value prevent any disclosure of such problems. Too Costly.

    It’s easier to blame someone else.

    Many additives and fillers used in product formulation are not tested over time. They are not significant enough to be revealed in the typical testing done by the major agencies, but over time can be disastrous.

    Ask some chemists and independent testing labs about additives such as fire retardant materials used in cap sheets of MB products. What do you think happens when a roof catches on fire that allows the roof to self extinguish? (a definition of FR or Fire Retardancy). An intumescent additive with controlled temperature reactivity exudes through the product to allow the FR function to kick in. How do they control this temperature reaction? How does it really function if only tested when the roofs are deliberately set on fire, not simply left to see what happens by elevating temperatures gradually?
    Can it vary over time? Can internal temperatures on repetitive extremely hot days set these chemicals off to exude, then migrate, and finally outgas to completely change the formulation significantly enough that blistering will not only occur, but flourish?

    Does anyone think the manufacturers did not know this could happen? And, if they didn’t, wouldn’t it be known very quickly after that first failure that caused them to know after the fact? When this happens in most consumer products, they issue a recall.

    How expensive do you think it would it be to replace roofs due to failing product sold by a major manufacturer of MB roofing all over North America? Millions upon Millions of squares of defective products. All waiting for something to happen. Think of the COSTS.

    No one has that big a checkbook, so they hide it. Then they play the blame game. Oh, the felts got wet, or the insulation got wet, or it rained, or the contractor didn’t apply the sheets correctly, or they did not broom the felts, etc. etc. Anything but truthfulness.

    Later, when complete refutation of all of their contrived excuses fail, they finally have to “reluctantly” consider that there “could be” something that they as manufacturers “might have had problems with”, and agree to handle “out of court”. That’s why we do not hear about these things. No court information, no exposure by the owners, consultants, or others involved because the settlements require everyone to not disclose these issues. Often requiring everyone to sign a non-disclosure form.

    These are not isolated situations. My guess is it is happening every day. We simply are kept in the dark. Why? Because there is too much money at stake. That is the principal behind every “conspiracy” being shot down. Big money can do a lot of things. But admitting their culpability is not one of them.

    They had to know.
    They knew
    But kept on playing the odds.

    It’s cheaper to buy problems after protracted deflection and blame, than make any admission of guilt. Just like the car manufacturers knowing a defective product would only cause 10 deaths for every 500,000 cars, it is a risk management decision.

    These are the true elements of the process that we will never know. These are the scariest parts of having product failures. These are the parts of the iceberg just below the water line. Failures documented by the “public” are only the worst 2-5%. There are many others just simmering waiting for the next batch of lawyers to defend to the point where finally they agree on spending money to fix those problems of the very few who will go the long distance for resolution to stay out of court.

    Today’s mantra in business is “transparency”. Good luck on getting transparency on these issues, it simply costs too much to reveal the facts of the materials and their problems.
    Wouldn’t it be great to hear from a “Truthful” manufacturer about these comments?

    Costs have been, and will be the driver of products. From inception, to litigation. COSTS are what the entire process is about.

    If the consumer would be willing to invest in something of quality, vs. first cost there would be significantly less failures because the products would have higher quality, single sourcing of raw materials, and protracted testing and continual follow-up to ensure a decent product.

    So, they hide behind meaningless warranties instead.
    The absolute BEST warranty, is NO warranty. Let the Uniform Commercial Code in each state govern how these product failure issues will be handled, and pretty soon the manufacturers will be forced to provide better products. The downside is, they will cost more.

    Don’t ever forget, warranties are developed and written by and in favor of the manufacturers. The Uniform Commercial Code was written to protect the consumer. Check out the terms and limitations in your individual state, and compare the “coverage” of both.

    More later.

    Keep up the good fight by exposing these manufacturers for what they are. Who is willing to name names? Somebody needs to. Maybe I will. Being sued is not a good thing, but it may be worth it to finally get justice for all of the fraud being perpetrated on the buyers of these problems waiting to happen.

    As Specifiers we are already exposing ourselves to terrific degrees of legal retribution, so what is the difference.

    One is our choice, one is theirs.

    Have a great day in this wacky world of roofing.

  11. With all the comment above there are no photographs, description, location, type of membrane i.e. fleecebacked, mil thickness, type of failure, mechanical attachment, fully adhered, urethane foam adhesive, full coverage adhesive, partially adhered, total TPO membrane roof assembly, magnitude of problem.
    Is there a real, or only a percieved, problem based on isolated occurences or opinion?
    Where are the class action lawsuits?
    Ardist Allen

  12. Rich,

    I have enjoyed reading this blog. I work for a MB manufacturer that does not cut costs to make a buck. We have to compete with the other guys based on performance rather than cost.

    Maybe it is our European roots and current connections, but our commitment to quality and our technical department’s conservative nature has us salesmen pulling our hair out sometimes.

    I am currently working on a project that CANNOT leak, and has to withstand 167 mph winds. The local consultant that I am working with wants to use our system, but the out of town “Consultant” wants to use TPO. All I can say is that this project is in south Texas, and last year we had at least 60 consecutive days above 100 degrees.

    How can I help my consultant battle this Northerner?

  13. Scott,

    Your comment, “I am currently working on a project that CANNOT leak, and has to withstand 167 mph winds. The local consultant that I am working with wants to use our system, but the out of town “Consultant” wants to use TPO. All I can say is that this project is in south Texas, and last year we had at least 60 consecutive days above 100 degrees.”

    What system are you recommending for south Texas? I am an asset manager in Oklahoma, right in the center of “tornado” alley. Had huge hail recently, so need to install flat roofs on 2 commercial buildings. A roofing contractor brought in by one of the principals on the project wants to use a 60 mil. TPO system and I am not convinced that is the product that would be best to use.

    Thanks, Diane

    1. Hello Diane,

      I need to let you know that Scott is a salesmen for a modified bitumen roof manufacturer, and his comment is an attempt to put PVC against TPO and somehow show that Mod. Bit. roofing is better. I am a believer that out of the three, the Mod. Bit. roofs are “not the best”. Yes they are durable, but besides that, the application method of either torching the seams or using cold-application (adhesive) will lead to leaks, and in some cases, fires on the roof. Also such roofs, often will not last more than 15 years without maintenance and repairs.

      I do believe that PVC roofs will last the longest with minimal roof maintenance, and will stand up to solar UV radiation and rain / hail, etc. Of course my opinion is subjective, but do understand that we are a contractor – not manufacturer looking to increase sales of the product. We chose PVc roofs after careful consideration of every flat roofing material there is – EPDM Rubber roofing, TPO roofs and Built-up roofing – Modified bitumen, Tar roofs, etc. We have complete freedom to sell and install any roofing system, and yet our choice is PVC roofing – and the manufacturer we chose is IB Roofs.

      As far as TPO roofs, after recent warning about TPO Roof problems issued by MRCA – http://www.coolflatroof.com/flat-roofing-blog/tpo-roofing/ – I would be very cautious about using TPO roofing, as apparently they are not very resistant to UV, as well as other issues.

      Best of luck.

  14. Long winded, but hey, I type well over 110 words per minute.

    I have worked literally all over the world, and I have one opinion after 37 years. If you start with the premise a given PRODUCT is the salvation to all ills, you are either a manufacturer, have very little direct experience with other systems, or have been brainwashed, or you’re just plain lazy.
    Did I offend everyone equally?

    There are no 2 roofs alike, and there is NO SINGLE system, regardless of type that will be effectively utilized, with long term success, on each and every project. Not Gonna Happen! Homey don’t play that!

    If you went to the Doctor and all he had to give you was penicillin, you would take it.
    However, when there must be hundreds of drugs for various infections alone, no single drug is effective for every case. To offer a single solution is (to me) indicative of someone who is working with blinders on.

    I firmly believe that you must go to the project, evaluate the conditions of the construction, the use of the building, the types of traffic, weather, sun, manufacturing nearby polluting the roof, jets landing nearby creating vibration, and about 25,000 other subjective elements to arrive at the MOST APPROPRIATE solution.

    Those of you, like me who are consultants have the freedom to do this, because we don’t have to worry about buying expensive machinery, teaching our crews how to do a specific manufacturer’s specification and techniques, then turn around and do this 5-10-15 times over to be able to provide “anything” that can be thrown at them.
    So, many contractors find something that has “worked” more often than another type of product, and slowly retreat to a comfort level with one or two manufacturers. Then because of volume, they become quite friendly with the manufacturer’s reps, go on junkets to the factory, and if it is nearby some great hunting or fishing, oh well, why not. Or Vegas, etc.

    I don’t care what contractors say, they are NOT free of bias in making decisions about which product to work with, not which is the most versatile for a given situation to actually SOLVE problems by “If you only have a hammer, everything looks like a nail.”

    I would challenge any contractor to debate openly their choice of products FOR A SPECIFIC ROOF CONDITION, not their favorite product.

    That’s not to say that there aren’t good products, regardless of type, brand, manufacturer (or in some cases just a marketer), but there is much more to the equation than simple installation of a branded product as mentioned in this blog.

    In many markets I find that the use of a particular type of membrane or system is largely driven by the popularity based on the contractors who dominate the market, the ability of the salesman, the strength of the distributors, and the climate, need for energy savings or rebates, etc.

    After all of this, I will still be asked What is MY FAVORITE ROOF. Well, to offer my candor on the subject, it’s one that fails regularly so I have a sustainable business model.
    In case you haven’t heard, TPO stands for Temporary Plastic Overlay. I call it my annuity plan

    But seriously, it isn’t just the product.
    Some of the most long lived roofs I ever saw were Coal Tar Pitch in the Carolinas. 50 or more years were not that unusual. And, these were put on back when no one actually did a design, or wrote a spec. The well trained “craftsmen”, working for a family company that had been in the marketplace for years, with credibility and when and if there was a problem, no one was going to sue, or fall apart looking for their warranty and starting that circus. No, credible businessmen took responsibility and did the right thing.

    Why did these roofs last 50 or more years?
    Specs were on Wood Mill Decking, Splined or Tongue and Groove, A red rosin sheet, cap nailed, a mopped two ply vapor retarder, Tapered Foam Glass insulation, and a 5 ply Coal Tar Pitch Rag felt, well put together with a heavy hand, then flood coated and rocked DAILY. At the completion of the installation, they would go back to the start of the project, sweep the loose gravel, and heavy flood coat it AGAIN, then more gravel.
    Very little maintenance, yet Performance was absolutely outstanding, beating anything since.
    Maybe simplicity is the answer. The chemical alphabet soup was mostly a choice made to capture market share by coming up with something cheaper. That’s not always a good thing, as proven by our industry. In the last 30-35 years, name one manufacturer, and one product other than a BUR that consistently lasted that long. I’m waiting to see it. I would pay to go and see it.

    Everyone puts down SPUF, but I have seen many 30 year old SPUF roofs at Texas A&M in College Station Texas, and it is HOT AS HELL there. Upkeep, and recoating are necessary, but at least Tear off is not needed.
    I am not a total advocate of SPUF, but I have spec’d about 1,000,000 sq ft. in THE PLACE WHERE THE ROOF dictated what was the most favorable, likely to succeed, and many other criteria that drove the decision towards SPUF.

    So, don’t preach about ANY product, generic type, or system until you open your eyes and decide to let the roof talk to you. Even Metal Retrofit could be the answer. You have to spend time adjusting your thinking, and get with the client, seriously question them, collaborate with them. Then together recommend something in 3 levels, good-better-best, and let them help in the decision. It won’t always be TPO, PVC, Glad Trash Bags, EPDM, or Peanut Butter. AND it won’t be IB Systems or Carlisle, or GAF, or whatever. You have to be versatile or you will be left behind.

    But hey, that’s just my thoughts on things. What’s yours.

    I have worked from South Africa with some God Awful UV problems since it is higher then Denver.
    to Japan, where many products WOULD work, temperate climate, but their parochial attitude keeps them from putting aside their bias and allowing for various imported products that could be beneficial.

    In some countries, Lake Trinidad Asphalt is used over Structural Concrete Decks. It’s the same as the LaBrea Tar Pits. Liquid asphalt self leveling, and unoxidized. You walk on it with concrete workers boots (long spikes on the bottom). NEVER WILL LEAK (well, not for over 200 or more years anyway.

    From Mass to Mexico, From British Columbia to the Island of Lucia.
    Guess what? Thatch is used and works very well in some areas. Go ahead and try and beat that with your IB PVC!!!

  15. For Diane
    I have several “mission critical” buildings for one of the Data Warehousing International Carriers. They too have high wind zone activity, and have had numerous problems with varying products over the years.

    Because of the temperature and humidity contolled interiors, An R-40 Insulation was required.
    Our response was to apply a high end liquid applied polyester resin system on the concrete deck, installed a single layer of Dow Extruded Polystyrene Insulation, and large Paver stones.

    The pavers primary function is to hold the insulation in place.
    They also have been very favorably looked upon as a high strength barrier to all sorts of “flying debris”, as well as Hail.

    A lot of our design was due to the specialty conditions of the site, the interiors, the client’s need and assurance that the building would not leak. The “Fix” was NOT inexpensive, but certainly cost effective when the Risk Management factors and Long Term Life Expectancy, the Life Cycle cost of the project, and many other financial modeling methods we employ in our consulting practice were put into the mix for the client to collaboratively work with us on reaching the decision we did.

    This is not a widely popular and well known material, and only a few specialty contractors have any major experience with it. I have had previous success with this product in another area of the country, and an associate utilized this on a major plaza deck in the Rockerfeller Center AREA, again, on a facility that flat out said, NO LEAKS TOLERATED. He has had NO LEAKS in over 10 years thus far, and it is a traffic bearing surface.

    Many other semi radical ideas can be explored when you have the experience a trained and professional consultant has working across the country, or over seas.

    Answers are there, you simply need to know who to ask.

    The “northerner” sounds as if he is applying his safety net of limited experience to suggest a product out of his comfort zone geographically, and has no real idea what he is getting into.

    PS, different insulation densities can make (Help actually), the “single” ply systems less likely to suffer as much damage from hail. Again, not a well known fact that ISO board and extruded or expanded polystyrene can be purchased in various PSI densities just for this inevitability.

    Call someone who knows. Hint HInt, Nudge nudge.

    As I have said in my earlier blog response, the consultant has a much wider range of choices in our pallet, and we do not have to rely on our staff’s training, and on-hand equipment purchased to install a generic material choice of TPO, or whatever it might be.

  16. This man is correct, I am a rep for a mod bit manufacturer, as I stated in my previous comment. I will also give him credit for choosing one of the two best PVC’s on the market, IB and Sarnafil. His comments about modified bitumen membranes could not be further from the truth. Yes, many of the polyester reinforced sheets on the market do not pass ASTM D-5849, Cyclic Joint Displacement, aged and/or new. As of late 2009, none of the fiberglass reinforced sheets, besides ours, pass this test. ASTM D-5849 is a true test of a good or bad modified blend. Another test which is a good predictor of a membrane’s potential lifespan is ASTM D-5147 section 11, Low Temperature Flexibility. The success of a membrane depends on many factors, method of application, mod bit blend, workmanship, etc. While the chemistry of a mod bit is very important, how it is installed, and who it is installed by is at least equally important. The contractors in my market have been carefully chosen based on quality of workmanship. Torch and cold application are the BEST methods of installing a membrane system, despite the previous comments about leaking within 15 years. I can show many roofs in the San Antonio/Austin area that are exceeding 20 years that are perfoming without a single leak. I have a torch installed roof on an arena in San Antonio that is on its 26 year, and it is still perfoming as it shoud. There is no reason for a mod bit roof, properly installed, to not last at least 25 years. If this is not the case, then the contractor could be the issue. One note, our company does not allow the cap sheet to be mopped on as of 1/1/09. Interply mopping can lead to problems down the road, and is entirely dependent upon the capability of the contractor.

    Bottom line, if you can’t install a mod bit roof without leaks, you probably should not be a roofing contractor.

  17. For the asset manager in Oklahoma, I have designed a two ply mod bit system over insulation over a concrete deck that qualifies for an FM 1-810, that is 405 pcf uplift.
    One thing to remember, tornadic winds do not act like straight line winds, and there will be debris which will probably damage the roof. It might be a good idea to install a primary roof directly to the deck, if concrete, or to a 5/8″ gyp board installed on a metal deck.
    As you are aware, a 60 mil plastic membrane will never be equal to a 200 mil elastomeric mod bit system.

    Diane, please give this person my email address so we can discuss this further.

    Thank you

  18. Peter,
    The link (below) you refer to does not appear to be a class action suit, more of a solicitation looking for evidence of defective Carlisle TPO membranes to build a class for a suit. The listing of current cases of this firm does not indicate that a suit is in litigation at this time. Where can one find a current or even past lawsuit involving defective TPO roof membrane. I for one do not believe there has ever been a previous suit or that a suit is currently in litigation. Comments?

    The national law firm of Lieff Cabraser Heimann & Bernstein, LLP, is currently investigating consumer complaints about thermoplastic-polyolefin (TPO) roofing manufactured by Carlisle Roofing System, Inc. Carlisle manufactures several models of TPO membrane and is used primarily for roofing commercial buildings. According to allegations made by consumers, Carlisle TPO roofing products contain an inherent defect that causes the roofing system to fail and allows leaks into the building.

    Contact National Defective Product Attorneys
    If you have purchased and installed a Carlisle TPO commerical roofing system and have experienced any of the problems described above, please contact a product defect attorney at Lieff Cabraser to submit your complaint. There is no charge or obligation for our review of your case.

  19. I am not impressed by this article. If you have a monkey install any type of roofing it will fail. The majority of roofing failures I have seen have involved faulty workmanship, and not product failure.

    The class action lawsuit is a firm trying to gather information to see if there is enough for a class action lawsuit. Read an article before you post it please.

    What does the fire have to do with anything? Are you saying that other flat roofing solutions don’t burn? Torch down and hot-mop can’t cause a roof to catch on fire?

    Please do more research before you categorically rule out an entire roofing system based on what is not impressive evidence. If you follow the logic of this article no one should ever install an asphalt shingle roof because the majority are installed improperly and will fail prematurely.

  20. Hi, I am a homeowner that has several buildings on my property with flat roofs. The previous owner only tacked corrugated panels on the joists, which is a poor solution for buildings under large trees. I want to remove the panels, put on some sheathing, and put up solid roofing. Today I received an estimate from a Home Depot rep who recommended that I install TPO. After he left, I googled TPO and landed straight onto this article. Thank goodness I have not committed to anything, but I am wondering if, since the last entry to this blog, any of these problems have been resolved. I certainly don’t wish to put anything on my property that will be a fire hazard or will last only 5 years.
    If the TPO issue has not been resolved, please head me in the right direction. Should I be looking for PVC roofing also, or is there an alternative for me that has not been discussed here? I realize that I am not a contractor or a corporate client, but as I am a homeowner I don’t want to waste my money either. I would appreciate any help you can offer.
    Thank you.

    1. Robyn,

      My recommendation would be PVC … it is the only flat roofing system that we install, and we made that choice because we know once we install it, it’s not going to leak, and we will never need to go back for repairs.

      We of course could be installing TPO also, especially that we have all the equipment for it, and could better compete with othe roofer, offering a cheaper option … however, just the the thought warranty calls makes me shiver.

      There is also rubber roofing, but with glued seams and flashing, for me it’s in the same league as TPO – not forth installing.

      Good Luck

  21. The 2007 TPO report from WSRCA did come out and was also published in Western Roofing Magazine in 2010 and gave a pretty favorable review of the test roofs up to that point. It also went into detail on the subject of membrane thickness and concluded that the loss had actually not been as significant as the previously published data might have indicated. We are working on the 10th year report and it will be out soon.

    1. Hi Michael,

      At the time this article was written, the report was not published. I wonder why it took 3 years to publish?

      I will have to read the report to make my own conclusions though. If I find that information in this article is wrong, I will correct it. Time wise, I don’t know when I’ll have time for this …. TBA

  22. Great- roofing article; now I’m even more confused. Being a home owner in San Luis Obispo,Ca. The wind blows 30 mph. 6 month out of the year. Right on my flat-1/4″ sloped roof at best. Weather is damp like the bay area.
    With this a economy, I haven a lot of money to waste on purchasing the wrong product. My research and gut felling is telling to go with a Poly glass-SBS-torch down. Need help; Thank you!

  23. Nathan
    Lest we forget, this blog is the creation of and edited by a contractor who is in love with Single Ply, with some great degree of specificity in his choices.

    Staying neutral is not easy, especially when a track record has been established over years that for HIM is working, and apparently quite well. He should be as aggressive as he is, simply because it is working…for him. Not for EVERYONE.

    Realize also, the experiences are based on weather, construction, codes, and myriad alternatives from across the continent about as far as you can go from you.

    I have many more options available as a specifier than a typical contractor, because they cannot be approved by every manufacturer, and for many good reasons, wouldn’t want to be.

    I am not going to presume to tell you the absolute best roof choice for your situation, because a thorough analysis hasn’t been done. Every Roof has alternatives, and sometimes more than one is equal in viability, but it is based on the individual condition, not the whim of a contractor.

    I will “suggest” however, the integrity of the applicator is very important to the project, then the manufacturer, and then the material.

    In my early career I was a multi-regional warranty administrator and technical services rep for a large multinational roofing company. The reality of warranties is a very strange situation indeed, because if there is a conflicting opinion of a valid claim, you as a small “buyer” of their materials have very little voice in the big picture.

    I was given a budget every year, and had to live and die by that number. I was also told that larger, national level clients came first, then the small one-off projects, churches, condos, apartments, and home-owners. If you made a claim in September, usually there were no budget funds left, so I would have to hem and haw, stall, not answer my phone, or whatever because you couldn’t tell a client there was no money available. That’s a reality.

    Consider as well, the asphalt roofing materials we know today have indeed gotten better. More quality control, better chemistry, better understanding of polymer asphalts, etc. AND, the system has 150- 160 years of experience. There are just as many bad jobs for each product type, it’s just not a statistic published for the consumer to know. However, asphalt is a proven product. Go back to my note about contractor’s being the most important part of the equation.
    There are only three things that can cause a roof to fail. Bad Workmanship, Bad Materials, and Bad Design/Specifications. Who controls two of the three?
    That’s right. AND, there is a decidedly skewed failure point by Contractors by far, vs. material failures, simply because the difference is working with the same manufacturing process, same chemistry, and quality controls vs. working outdoors trying to do brain surgery in a swamp.

    For what I can tell about your comments, you would be satisfied with your choice, and do just as well on a small roof as another type. Regardless of other’s input after I make such bold statements that are sure to raise the ire of the “ONLY SINGLE PLY OR DIE” guys. Sorry fellas, you must be more open minded. There are other choices, but if you’re happy fine, just don’t presume to tell someone across the continent what materials he should use if you’re not working in that market.

    Do you recall (probably not) the days when if you had a bug, the Doctors used penicillin for everything? Why? Because it was available. Now there are choices based on INDIVIDUAL circumstances, and NO PRODUCT is a panacea for every roof in America. If that was even close to the situation, don’t you think a lot of companies would go out of business and succumb to their stupidity because they didn’t choose to align themselves the same way?

    Give it a rest. We know you have an agenda, and it is so grossly exploited it’s laughable. I know it works in Boston, but that does NOT mean it works in San Luis Obispo. OR California, or Alaska, or the Antarctic, or the rain forests of Brazil.

    just saying…….

    1. @ Rich,

      At first I was going to disallow your comment, due to some of your previous comments, where you blatantly posted personal “attacks” against me and my company, ON MY WEBSITE!

      Note – those comments are still “in moderation”, and I will not approve them. Also, I wrote you a personal email to which you never responded – would you care to do so? I can find a copy of it and send it to you again, if you deleted it (which I think you did).

      I did however approve this comment, and did not remove the link to your website, where I cannot leave comments.

      Yes this is MY WEBSITE and I will post here the information that I believe to be true, and beneficial to my readers! I will not allow comments that attack me or my company! You are not alone – I recently had some dude from NH who posted VERY rude comments – NOT APPROVED here :)

      That said – yes, IB Roof or PVC roofing or single ply roofing in general may not be the best option 100% of the time. However, it works in 95% of the situations and does so very well (IB Roof in particular, and since not all single plies are the same, I will from now on talk about this particular brand of PVC roofing).

      What are the alternatives for most flat and low slope roofs?

      Rubber Roof (EPDM), Modified Bitumen (Mod. Bit.), TPO, rolled asphalt (really – who even installs that junk anymore?), Built-up roofing (BUR) – a combination of tar / asphalt saturated roofing felt with hot-mopped tar or asphalt, with or without gravel. There are also products such as GAF Liberty, which is a form of cold-applied mod. bit., sometimes with TPO base ply, and similar products from other asphalt roofing shingles manufacturers.

      There is also Spray Foam Roofing, and some other “exotic” roofing materials and coatings, but those are rare.

      So, most “popular” choices are Rubber, Mod. Bit., and TPO as of late. All of these, except for TPO are problematic due to seam failures. TPO is unproven, and I won’t be getting in the whole TPO debate right now.

      Mod. Bit. – whether cold applied or torched – how do you expect two plies to stick together well, if there are granules between them??? I do not mean specially made seams without granules – I mean in field penetration flashing. That will certainly leak and rather soon. Also, any ponding water and your warranty is null and void.

      A smooth surface Mod. Bit. has same problems as rubber roofing, explained below.

      Rubber roofing – same story – glued seams and with time, glue breaks down and fails = roof leak!

      IB PVC roof’s seams are hot air welded, and when it comes to MY WORK – they do not leak! I agree that much emphasis should be put on the contractor installing your flat roof, but choosing a “defective” roofing material will have its consequences as well.

      Bottom line – IB PVC flat roof works for me and it works great. But it also works for MANY other responsible roofing contractors in Alaska, California, Colorado, and all across US. Keep in mind that IB Roof Systems is an Oregon based company, and most of their installer base is on the West Coast and on the Western half of US in general.

      I use IB Roofs because I KNOW they will not leak after WE install them. I do not have such faith in other roofing materials. And I am open minded. Do you think I don’t know how much business we loose to cheaper Rubber and TPO roofs? You think I’m not tempted to start offering those? I am! Almost every week I give this a good thought. BUT, I know that I will be doing disservice to my customers and myself. Yes, it will create a nice “job security” for me and many other roofers, but I keep pretty busy cleaning up after those other roofers who’s 30 year roofs fail in 10 years, beyond repair. Many rubber roofs that we repalce are UNDER 3 years old – but this is mostly due to HORRIBLE installation. Here is a video I made to demonstrate crappy rubber roof installs:

      To summarize, I believe that IB PVC roof is one of the best flat roofing materials on the market, and alternatives are not worth wasting time and money on them. And yes – it will work for Nathan, and probably be the best choice.

  24. Good evening,
    I posted back in January concerning your roofing system. Your answer appeared in May, after I completed my project. I am now receiving emails with links to your website blogs. Please take me off your emailing list. Thank you.
    Robyn

  25. Leo
    Would you please send the email again, and your return email address.
    I would like to make additional comments, off-line, so to speak.
    I am not a flaming A-hole as you might have deduced. I am trying to be fair and balanced, but some things obviously we disagree on. And that’s fine. I disagree with my wife of 42 years too.

    Thanks for your input, and let me know.

    Rich

    [ADMIN]
    Rich – I moved this comment here, to “streamline” the conversation. No reason to post this in other articles, where it makes no sense. PS – I resent the email AS-IS with no changes from the original.
    [/ADMIN]

  26. I just had a TPO roofing system installed on the flat sections of my home. My expectation was that it would be super flat to the roof. The installation is not flat and appears to have many “air bubbles” underneath the material. It has almost loose appearance. Is this the way a new installation is supposed to look?

    Thanks!

    Lou

  27. Anyone who uses a generic name like “hypalon” in their comments is not informed. J.P. Stevens is the “hypalon” that failed because they constantly dumbed it down and changed the formulation. Burke Industries made a hypalon sheet with a higher percentage of hypalon, less fillers, etc. We have roofs that we installed in 1987 that are still in service using Burke. We installed a 36 mil Burke Hypalon that has never leaked in 19 years. Stevens ruined the Hypalon market with a terrible formulation. Burke Hypalon is still the best sheet that I have ever seen. And, that’s 34 years of single ply roofing talking. PS: And, I know that Hypalon is a duPont trademark for Chlorosulfonated Polyethylene…….

  28. Hello,

    I am a commercial roofing project manager and owner’s representative as well. It is interesting to look back at the years of comments on this article. While there may be more geographic factors contributing to some membrane failures most of what I see on the project is not strictly bad product but a combination of the right product in the wrong application. When properly applied a current membrane is going to give the owner between ten and fifteen years of service. The systems discussed in this article are susceptible to UV, temperature swings and improper installation. Furthermore a roof in Seattle will have a longer lifespan that that in Denver. Our job as roofing professionals if to educate without being inflammatory. Our clients are intelligent enough to make the right decision.

    Exposure to liability is really not the motivator for performance with the manufacturer or installer. We are all doing the best we can. At this point TPO, PVC, EPDM are all appropriate for different applications. It’s up t all of us to make sure the right roof gets installed and installed properly.

    Keep up the good work all.

  29. Leo,

    This is your website and you moderate the comments. Fair enough. Could you please disclose how many positive comments have been posted about TPO roofs that you have “disallowed”? Perhaps none, but perhaps many, thus skewing the conversation. I am a homeowner researching options for my flat roof in Los Angeles. Three roofers have given estimates and each strongly prefers a different material. One spray foam, one bitumin, and one TPO.

    Thanks,
    Paul

  30. Paul,
    Please do not consider a polyurethane spray foam in any way a roof. These guys are hacks selling snake oil. This “roof” may last 3-5 years, without any hail, punctures from traffic, or birds pecking at the foam. Save the foam for the walls!!

  31. Since 1982, I’ve been in the single ply industry. As an EPDM tec rep, a KEE tech rep and the last 20 years as a sales rep, regional mgr and now independent mfgrs rep. I have walked well over 100 million square feet of all types of roofs over 23 states in my travels. So I have seen a ton and have 1,000s of photos. Having said all that, there is no doubt that TPO membranes are having widespread failures, anyone that would say anything different is clueless. Just go walk some 5 to 10 year old roofs around the country and the evidence is there. They are addressing the formulations but who knows when they will get it right. If the roof has ponding it increases the failure time. If the roof has parapet walls that increases the failure time. Any windows or reflective materials that cause a heat gain on the membrane will also accelerate the process. If you have to use it then I would only use 80 mil TPO and only with tapered insulation to remove all ponding on the membrane, that should really help out. If fire is an issue then don’t consider TPO, it burns like paper. If grease or oil is present don’t use TPO either.

    I represent Fibertite a KEE single ply membrane that has roofs that have lasted for over 30 years in almost every state in the US. Unfortuately our cost is double that of a TPO membrane, so expect to pay about $0.50/sq.ft. more for a proven product. If you need additional info just let me know.

    1. Hi Jim,

      I would be very interested in seeing some of those pictures that you have and asking you a few question.

      Is there a way for me to contact you?

      If you do read this response, please shoot me an email – leo @ coolflatroof.com (no spaces).

      I will also email this to the address you provided.

      Leo.

  32. Can you send me a link to the Western States Roofing Contractors Association TPO roof study. How do they know a TPO roof looses 1 mil of thickness per year. Thanks

  33. Articles on various materials for flat roofs are very informative.
    After removal of two BUR installs (50 years old)down to existing roof deck, had a Firestone UltraPly TPO (.060 Thickness coupled with 1/2 inch high density wood fiber roof insulation) installed which have some “air pockets” Is this normal or due to poor installation? Need a professional opinion & someone or reference to consult. Thanks: R.C.

  34. Enjoyed your articles on the various roofing materials available for flat roofs. Had a two layer BUR which was removed down to the decking & went with a Firestone Ultraply TPO (1/2″ insulation insulatiocoupled with a
    60 mil

  35. HELP! We have a small single family home and we want to install a white flat roof over an addition that is only 1219 sq. ft. We will use the roof as a patio and do a bit of soil-free gardening. Which product is right for us on a limited budget? We need a roof that has a 20 yr. – 30 yr. guarantee. Any advice?

  36. TPA is not a TPO. The are both white membrnaes, but the comparison stops there.

    TPO is a thermoplastic Polyolefin.

    TPA is a tri-polymer allow, which is CSPE, PVC and Elvaloy.

    TPAs have a far better history of performance and stability.

    Hold a sample of each (same mils) and you can see and feel the difference.

  37. I have recently ran into issues with a Fibertite PVC system.
    The owners are experiencing leaks caused be rodents and insects actually attacking the membrane.
    The fact that Soy based products may be used in manufacturing has caused suspicion leadngntothisb phenomenon.
    Does anyone have any information concerning other users that may be experiencing the same or similar circumstances?

  38. The bottom line is that about 8-10% of the entire roofing market agrees with this. That is the market share that PVC enjoys in the U.S. & has enjoyed for years without change. Websites like this have no chance of changing that.

    The End

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