Recently, the MRCA (Midwest Roofing Contractors Association) issued a warning bulletin regarding TPO roof failures caused by the sun’s UV rays. You can read more about it on our original TPO Roofing page, as well as my commentary on this bulletin.

At the same time, major roofing distributors are shamelessly pushing TPO into the market and onto the roofing contractors without much regard for home and building owners. Bear in mind that because of low prices and “same cool roof” and “welded seams” qualities as PVC roofing has, TPO roofing is now the fastest growing commercial roofing product.

Here is a good example – pictures below will show you “manufacturer’s” stand showing a TPO roof designed for residential roofing contractors.

Why residential roofing contractors? Well, the way I was told, these are the roofers who can’t afford to spend $12,000 on hot-air welding equipment, so the roof manufacturer created a system so these guys too could jump on the TPO band-wagon.

(The TPO stand above, is displaying outside corner flashing, inside corner flashing, pipe boot, and drip-edge details. When I asked about the caulking along the seams, i was told it’s not caulking. It’s seam tape )

Here comes the best part! This TPO roof system is put together with … no, not hot air. Seams are primed and a seam tape is used to seal overlaps! But, it gets better – since there is no uncured flashing material in the TPO world, and these “shingle-bangers” don’t have Liesters (hot air welders) nor do they want to buy them, since the cheapest one – a hand welder – is $450 before tax. So, this manufacturer uses white EPDM uncured flashing for all detail work such as inside / outside corners, posts, curbs (skylights, chimneys, roof hatches, HVAC equipment, etc.). EPDM rubber on TPO – really?

So basically, here is what you – the roof owner get: An untrained, inexperienced roofing contractor, installing a roof system (TPO roofing) which is unproven, and there is a good chance it will fail, using flashing materials made for a different roofing system (EPDM rubber roof). And you loose the only real potential benefit of a TPO roof – hot-air welded seams, since now all your seams are glued together, just like rubber.

So I want to know who wins? The manufacturers, the distributors, and partially the roofing contractors – but not the homeowner. Why? The manufacturer sells the membrane and accessories, without giving a warranty for the product, since the contractor putting it down, in not trained / certified. Distributors will always get their cut, and contractors who screw up their work, usually disappear. So you, the roof owner will be left to pick up the slack on repairs – kind of sad I think…

Excerpt from a TPO roofing discussion at Roofing.com forum:

The post bellow, is my reaction to recent discussions at Roofing.com – one about Pictures of failing TPO roofs, and another one, which started as a homeowner’s question about an IB roof, and turned into a discussion about TPO vs PVC roofing.

If you do not feel like reading the two Roofing.com posts linked above, I will mention that Donl is a site admin at Roofing.com and Cerberus is a very knowledgeable (in my opinion) roofing consultant from Texas, and is an active participant in Roofing.com discussions.

The reason why I’m posting my response here – well, I feel that putting it on my blog instead of at Roofing.com will benefit you much more. There, only interested roofing contractors will read it and then the post will disappear in a week or so.

To Cerberus and Donl:

Guys, I respect your knowledge and experience, of which you have more than I do. At the same time, it seems strange to me that you both defend TPO so actively – here is why:

Putting IB Roofs aside, I do believe that TPO is a bad product (here in the US). But besides that notion I have to say that although these pictures ( http://home-and-garden.webshots.com/album/559881410NjElbu ) are from ’97 and the membrane was made around 1990, what has changed?

Also, it should be noted the sheets some are showing as failed TPO are from the early years of TPO roofing before there were ASTM testing criteria. Things have changed, so someone showing a failed TPO membrane from the 1990′s is like me showing a failed Carlisle EPDM roof from back when they were using N-100 Lap Adhesive instead of EP-95 or Seam Tapes; it is deceptive!

Cerberus – when you point out that it was one of the original TPO membranes that failed, do you really know what we as an industry are dealing with now?

Do you know what exactly is sold at a local Bradco or ABC? Which formulation is it and how long it will last? Not a single TPO manufacturer will tell you what you are buying – they will never admit that they have a problem, unless it is a HUGE f-up.

Can you possibly know when this TPO will fail or will it last 15-20-25 years? No, you can’t know that, judging from what the TPO manufacturers are doing, which is changing the formulation every few years. And why? Is it because the previous formulation failed? And maybe to put even more fillers in the product to make it cheaper?

As much as I don’t like EPDM rubber roofing, as a flat roofing product, at least with it you know what you are dealing with: Membranes won’t fail. It will be the seams that will start leaking. So you can plan accordingly.

With TPO, you have:

- premature curing
- seam failures
- loss of thickness
- and now we find out that “some” TPO’s can’t take the UV

Yes, TPO is taking over the commercial roofing market, and as you Cerberus rightfully pointed out – merely because of its low price and Cool Roof / Welded seams features…

I don’t know about you, but I won’t touch TPO just because I can’t put my name on it.

Do understand that I’d love to work with it – it costs much less than IB and I can get it locally. And because it’s cheaper, it would be MUCH easier for me to sell it! Instead I have to fight the competition which sells both rubber and TPO for much less than I can.

But what do I do when it fails, or the seams come apart, or the water separates the sheet through wicking scrim?

I go with a product that I personally can trust – not something that seems good on paper, and is cheaper and easier to sell to a customer.

And tell me this Cerberus. When I was asking people on this forum for good pictures of failing TPO roofs, you asked me: ” “Why? What are you trying to do?”

Well, I feel and know that TPO roofs are failing (some are here in Boston, and I can’t talk about it) but manufacturers won’t let people talk about it and specifiers can not say that – yes, TPO roofs are failing – because they already specified 1000s of squares. And roofing contractors won’t talk… and now one can say names. And I would probably also keep my mouth shut if I had a lot to loose .. fortunately I don’t work with TPO … And when I work with PVC, I know that it does work. I repaired an old IB (7 yrs. old) and it welded just fine. I repaired an old Sarnifil (20+ yrs. old) with IB and it welded almost just fine. I even repaired a cracked Trocal (about 25+ yrs. old) roof with IB and after cleaning off the dirt, it welded just fine. So yeah, plasticizers may leech out, membrane me shatter (and actually does when it’s Trocal ) and so on and so forth, but PVC works!

So what I was trying to do is to get information / evidence (pictures) of PVC and TPO roofs that are failing.

And you know what – in the end, it will come out. Or manufacturers will bite the bullet, quietly replace failed roofs and finally get the formula right (by not removing the components that make the system work)… but they will make less money…

Just my opinion…

Additional materials about PVC and TPO roofing:  TPO Roof failures.

TPO vs. PVC conversation – continued on Feb. 23, 2010

Quoted text is the response from Cerberus posted 0n Feb. 22, 2010:

And while you addressed your post to both myself and Donl, you seem to actually be directing the post at me. So, here it is in a nutshell.

1st – I’m not totally 100% comfortable with TPO yet, but that is because as a consultant I like something with a long successful track record. I know that TPO roofing is in its infancy, and like EPDM, Mod Bit, and yes, even PVC, systems in their infancy tend to have problems that need to be ironed out. In the meantime, as a specifier I am required by local codes to specify a roof with 70+% reflectivity and .70+ emissivity. In other words, I can choose between TPO and Derbibrite since PVC membrane isn’t popular in Houston.

2nd – If I was going to use a PVC roof, it would only be Sarnafil. However, now that it is Sika-Sarnafil how do we know they won’t play with the formulation? You asked me that question about TPO, so I am turning it around on you. Afterall, the first thing Firestone did when they purchased Rhoflex mod. bit. was change the formulation and make it cheaper in both quality and price.

I did address both you and Donl. Its just that Donl did not really defend TPO – more like bashed IB 

Anyway, one by one:

Am I starting a witch hunt? NO! … I know of enough TPO failures and some big ones here in New England, but I’m not at liberty to disclose them and can’t compromise my sources.

I really don’t care that much for TPO – I understand that people want to save money and will 99% of the time go with a cheap option – not quality. This is especially true in the commercial market, which you (Cerberus) represent. In residential roofing things are different and TPO guys don’t know how to market to homeowners – therefore I don’t care much about TPO unless we are bidding on the same, usually commercial roof.

My problem with TPO is fundamental – until manufacturers stop “scamming” their customers (roof owners and contractors) by putting out crap products, I will have a problem with TPO. When they make TPO a good product, I will like it, but it won’t be as comparative, and PVC will kick its butt Pictures I needed as visual content.

Now about specifying practices: Basically from your last post I conclude that you will specify a roof that you are “not totally 100% comfortable with TPO yet” because local codes requires roof to be 70% cool and people are not willing to pay premium for PVC.

Also you as a roofing consultant know more than most people here do, and certainly much more than your “customers” – that’s why they hire you. I don’t understand why you would “withhold” information about TPO from your customers? Both Good and Bad.

Why did I use the term “withhold”? If you told them about high risk potential of their TPO roof failing withing 7-10 years, they would not buy it. Therefore, I assume you do not enlighten your customers.

I want to stress the point that a recent MRCA advisory about TPO roof failures concerns mainly the southern US – your territory with high temps and constant UV exposure.

The Bottom line – TPO gets specified because it’s cheap – not because its good, and at the expense of building owners.

I don’t specify mod. bit., TPO, BUR, or any one roof for every building, and I certainly hope you aren’t only selling PVC for your low-sloped roofs. To do so either shows you are limited by the manufacturer’s approvals you can get, or lack of knowledge about other types of roofs.

Maybe I do lack both knowledge or manufacturer’s approvals 

You know – I can buy pretty much any roof I want – TPO / PVC / EPDM or even mod. bit. without manufacturer’s approvals. I won’t. I won’t install rubber because it will leak (not right away of course, but still). I won’t install Mod. Bit. … well I never did and don’t want to learn because in my opinion it’s inferior – those seams will separate and the roof will once again leak TPO I just don’t trust. So that leaves PVC which I’m very comfortable with and, since we do not do skyscrapers, it fits our needs 99% of the time. Only once we had a roof for which PVC would not work, but the customer was not willing to pay $2000/sq of Soprema liquid-applied (not coating) – He wanted Rubber for $450/sq. Well I think that’s what he got .

So yes – most of the time I will prescribe PVC.

Written by Leo - roofer with a vision. Follow Leo on Google+