# Commercial Roof TPO vs. PVC vs. Modified Bitumen



## 1985gt (Dec 10, 2010)

briguyis1 said:


> 1985 GT... I will say one thing. I think FiberTite is better myself. So you won't find me shouting from the mountain tops for Duro-Last. Shame they are not responding.
> 
> Debate aside, every roof systems and every manufacturer has their strengths and weaknesses. I just don't like when people GENERALIZE and call one type or one manufacturer 'GARBAGE' or 'CRAP' just because they are tearing them up.
> 
> With that being said, PVC has a lot of strengths but it also has numerous weaknesses. As does TPO. As does BUR. As does MBR. As does SSM. At least we can most likely agree on that?


I very rarely talk bad about any roof system in a whole, save for SPF roofs but that's a different story. The duro last failures are fairly well documented. I will admit I do not know on their thicker membranes how well it performs, most everyone I have seen have been the 32mil or whatever thickness it is. Look at what happened with Trocal, they now seem to be owned by Sika, who owns Sarnifil. I guess that has everything to do with what happened to their PVC in the 80's.

10-15 years ago we were tearing up a lot of asphalt and gravel roofs, one of my all time favorite roof systems, these were anywhere from 15-50 years old, not junk by any means. Compare that to now and it is a lot of ballasted EPDM's anywhere from 10 to even 30 years old. While not a great roofing system, it is a viable one.


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## briguyis1 (Nov 18, 2015)

Well, there lies one problem. Are you tearing up Type 4 Durolast? Probably not! This is why it is important to know GRADES AND TYPES! 

Trocal? Trocal blamed it on their plant in Germany. Doubt it! It was because the membranes were not reinforced! Remember it well. Stuff was shattering and cracking all over. Which brings up another point. When people start bashing TPO based on 1st generation failures while claiming PVC is superior, yet fail to fully disclose PVC has ALSO had numerous documented failures, namely Trocal, their arguments fall flat.

When TPO roof membranes first hit the scene in 1989 and soon emerged in the marketplace in the early 1990s, manufacturers originally developed TPO formulations primarily for UV resistance- with guarantees of energy savings. Sadly, many of the first generations of TPO failed miserably and quickly garnered a gamut of negative reviews-from building owners and roofers alike. Turns out, first generations of TPO did reflect UV rays, but at the cost of membrane degradation. Early generations of TPO that failed were typically installed around highly reflective ductwork or below highly reflective glass, where the sun is reflected back onto the membrane much like a magnifying glass. This resulted in surface temperatures (reportedly as high as 300° F) well above what TPO was originally designed to handle, causing many TPO membranes to curl, become distorted and turn yellow resulting in membrane breakdown. 

Simply put, word spread quickly about these failures and predictions of TPO’s demise began to quickly increase in the early 1990’s. Even today, many ill-informed so called roofing experts speak poorly of TPO based on early first generation failures. Problem is, today’s opponents and critics of TPO are basing their opinions on past history and not current performance. For the more informed, the concern today regarding TPO is not so much ‘membrane failure’, but more so improper installation. According to the NRCA, 49% of all roof assemblies installed today that have experienced failure of some sort...fail because of contractor error and improper installation and NOT from manufacturer’s defects. As a matter of fact, studies show only around 8-10% of ALL roof failures including asphalt shingles etc. are a result of manufacturer’s defects. So clearly TPO manufacturers are doing something right today to rise to the number #1 most installed roof assembly in this country, yes? One would think so.

Originally, there existed no ASTM standards for first generations of TPO, so it is understandable why there existed many critics of TPO in it’s early years of existence. After TPO was developed for commercial roof assemblies, it actually took almost 14 years for ASTM to set a standard for TPO. In 2003, ASTM D 6878 standard titled “Specification for Thermoplastic Polyolefin-Based Sheet Roofing” was born, and required TPO manufactured membranes be able to withstand 240°F for a minimum of 4 weeks, or 670 hours. But as mentioned previously, with surface temps of TPO reaching as high as 300° F around reflective surfaces, many argued it wasn’t enough. Nevertheless, at least a standard was put in place and at the very least, it insured an improvement over previous generations of TPO membranes. 

As the years passed, ASTM made several minor revisions in 2006 to their original standards set in 2003. However, in June 2011, ASTM revised their D 6878 standards for TPO to address bigger lingering concerns of prolonged exposure in extreme heat climates. Today, TPO is required to withstand 32 weeks, or 5400 hours, at 240°F without significant changes to the membrane’s physical properties, representing the most stringent and demanding heat-aging requirements of any single-ply roofing material on the market. The current ASTM standard represents a substantial 800% increase over the previous standard. In addition to the new requirement for resistance to extreme heat exposure, the current ASTM standard (D 7635) also increases the required minimum thickness over scrim for TPO membranes. The revised standard now requires a minimum thickness of TPO over scrim of 15 mils – a 25% increase over the previous standard of 12 mils. The thicker the top ply of TPO, the longer it should last. 

In summary, the current ASTM D 6878 TPO standard for heat resistance is equivalent to subjecting any thickness of TPO membranes to 185°F for six hours a day for 20 years. With TPO manufacturer’s recognizing early failures and with ASTM standards for TPO stricter then ever before, the quality of TPO being produced today is significantly better versus previous generations and will assure a marked improvement in performance versus previous generations. In my view, TPO is now proving itself to be a very durable, sustainable, and high-quality roofing membrane. 

Yet there always exists plenty of so called experts who will still call TPO crap because "I tear that stuff up everyday!" Perhaps they are but it's a lame argument. It's not ALWAYS the membranes fault.


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## 1985gt (Dec 10, 2010)

Actually yes it was type IV since 40 mil is their thinnest sheet. I thought it was thinner, I guess I was wrong. 

Early generations of every roof system had issues, 

PVC when it was being produces unreinforced failed terribly in colder climates. Some sheets still have issues with the cold.

EPDM has had a lot of issues over the years, from the seams, to the cured tapes dry rotting, Neoprene corners, Goodyear PE metal (that was a good idea ), Pin holes starting from blemishes, still see that one.

TPO Issues with the heat, both solar and from over heating welds, cover tapes delaminating, Issues with welds, ect.

Asphalt, organic felts.... crappy modbit sheets.


Not sure why you are going on and on about TPO. I'm no sure anyone in this thread called it crap, it's a very viable roof and we install our fair share of it, or 3 main systems are EPDM,TPO and asphalt, whether it's a 3 ply and a cap sheet or felts and gravels, if you can install it in hot we will mop it down. We hardly ever install any PVC.

If we didn't like TPO we wouldn't have to Robot welders, 4 hand welders 2 Rhinobond machines with 2 sets of extra magnets and two large generators to support the equipment. That would be a heck of a lot of money just sitting there if we were "bashing" TPO.


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## 1985gt (Dec 10, 2010)

To add I missed when you edited your post to have me answer all of your questions, I'll have some time later to do so if you still need the information.


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## A&E Exteriors (Aug 14, 2009)

briguyis1 said:


> And let me guess, it was the membranes fault on every failure and not the installer, right? Funny thing is, the vast majority of roof failures is due to IMPROPER INSTALLATION! But amateurs like you form negative opinions about materials or assembly types based solely on the fact that "I've tear this stuff all the time." Really? I tear up BUR roofs all the time but I don't bash them. I tear up PVC and TPO but I don't bash them. I tear up modified bitumen roofs but I don't bash them. I tear up EPDM but I don't bash them.
> 
> Just because you've torn up several Duro-Last roofs doesn't mean the PRODUCT is garbage. Perhaps the install was incorrect. Perhaps it wasn't installed according to specs. Perhaps it was installed when it was too cold. Perhaps the roofing company didn't adhere the membrane properly. Perhaps the hot air was set to high, breaking down the weathering properties of the seams. Perhaps the owners didn't do annual maintenance. I could go on and on and on. There are dozens and dozens of reasons why roofs fail OTHER THAN "I've torn up several such and such roofs so therefore it's garbage."
> 
> ...


Salesman is why


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## A&E Exteriors (Aug 14, 2009)

briguyis1 said:


> 1985gt...Let me make this clear. I am in now way affiliated with Duro-Last. I have no connection or loyalty at all to this company. With that being said, Duro-Last has installed over 2,000,000,000 square feet of their product. That's 2 billion SF. This makes them the largest in the country. So let me guess, you have personally examined all 2 billion square feet of Duro-Last in North America, yes? Because if you have, then maybe people would respect your OPININON. And how to do you know it's membrane failure due to manufacturers defects? And if is, did you instruct the owners of the building to have Duro-Last reps come out to verify the membrane failed due to manufacturing defects? After all, there should be warranty coverage yes? Do you have a letter from Duro-Last stating they agree- the roof failed due to manufacturer defects and that they will cover it under warranty? Do you have any other proof besides your opinion and few pictures?


While you are spouting off IB can be welded at 30 years old


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## madrina (Feb 21, 2013)

Watch your mouth boy!! 1985 ain't no amateur! He's probably one of the most experienced roofers on here.. 
Now, let's start over. 
I just wanted to say hello and welcome to contractor talk.. first of all, thank you for posting that crap flyer, it's been a long time since we had any action over here. Secondly, thank you for writing a post so long that even I wouldn't read it. I graciously hand over my title and crown for long winded posts and 3 thank you for getting so pissed off because it makes everyone laugh. Especially me and 1985. 

Oh and thank you for writing in paragraph form, it makes it much easier to skip thru sections of useless information, such as in your first few posts, when you say, installation error, we understand the wide range of possibilities that term encompasses, so for you to waste yours and everyone else's time listing every single one of those possibilities, undoubtedly, to prove you have some actual tar under your boots... well... its.... its... it's like, getting a blow job and your mom calls.. ya know, like I'm enjoying this.... things are getting interesting, and then bam, you lose me. I'm scrolling and scrolling and then I determine that I just don't have the time it takes to get involved here. And ya know I might have learned something today if you had ever learned to summarize.


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## 1985gt (Dec 10, 2010)

madrina said:


> Watch your mouth boy!! 1985 ain't no amateur! He's probably one of the most experienced roofers on here..
> Now, let's start over.


Now that's not true! I may not be an amateur but there is plenty here who have a whole lot of experience. I've got two left thumbs and a nail in my head when it comes to shakes/slate/or tiles. I like to step as hard as I can in the middle of Spanish tiles because I like to hear the cracking. :whistling



madrina said:


> it's like, getting a blow job and your mom calls.. ya know, like I'm enjoying this.... things are getting interesting, and then bam, you lose me.


:laughing:


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## Sarfiras (Jan 14, 2016)

This discussion has been going on for a while. I hope the OP has got his roofing done. I had found myself in a similar situation back in October, but did not search any forums for answers, regret it now. After having used TPO for the roofing, I can clearly say that it has it's benefits. Not only is it durable, but also is cost effective and easier to install.


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## 1985gt (Dec 10, 2010)

all brought you by the good folks at empireroofingcorperation...


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## madrina (Feb 21, 2013)

Well there you have it! The not already established, luke warm, unbiased, uninformative deciding factor.


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## Sarfiras (Jan 14, 2016)

1985gt said:


> all brought you by the good folks at empireroofingcorperation...


Yeah, I got it done from Empire Roofing Corporation.


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## madrina (Feb 21, 2013)

So you did your own roof? Or are you a roofer now because you chose to put a tpo roof down.


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## AlabamaSummers (Feb 14, 2017)

*You're mostly right....*

Just reading a very old post but felt compelled to add this comment. I just wish that people would respect each other's feelings before posting things.

It seems clear to me that your logic, objectivity, and general critical reasoning is much better than the other guys. But I wanted to mention one thing that might make a big difference in your life.

Even if you are right most of the time about stuff, people are really going to hate you for the way you said it. The reason is because you hurt their pride. Ironically, you said it that way because of YOUR pride. It felt pretty good to bully a guy and put him in his place. I do it all the time too but I've beginning to realize that the pride I feel is not as much as the humiliation as the other guy feels.

PS. You hit the core of the problem in your response but I kinda' disagree that you can rely on manufacturer's numbers. They really pump them up. So, it's like comparing everyone's pumped up numbers. lol. And market share doesn't necessarily mean the best product. Sometimes, good marketing goes a long way.



briguyis1 said:


> And let me guess, it was the membranes fault on every failure and not the installer, right? Funny thing is, the vast majority of roof failures is due to IMPROPER INSTALLATION! But amateurs like you form negative opinions about materials or assembly types based solely on the fact that "I've tear this stuff all the time." Really? I tear up BUR roofs all the time but I don't bash them. I tear up PVC and TPO but I don't bash them. I tear up modified bitumen roofs but I don't bash them. I tear up EPDM but I don't bash them.
> 
> Just because you've torn up several Duro-Last roofs doesn't mean the PRODUCT is garbage. Perhaps the install was incorrect. Perhaps it wasn't installed according to specs. Perhaps it was installed when it was too cold. Perhaps the roofing company didn't adhere the membrane properly. Perhaps the hot air was set to high, breaking down the weathering properties of the seams. Perhaps the owners didn't do annual maintenance. I could go on and on and on. There are dozens and dozens of reasons why roofs fail OTHER THAN "I've torn up several such and such roofs so therefore it's garbage."
> 
> ...


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