Understanding Roof Restoration Episode 2 - Recovering TPO, PVC, EPDM, and Other Interesting Single Plies - PODCAST TRANSCRIPTION

Editor's note: The following is the transcript of a live interview with Greg Hlavaty and Hal Leland of Western Colloid. You can read the interview below, listen to the podcast, or watch the webinar.

Karen Edwards:

Hello and welcome to the Understanding Roof Restoration Podcast. I'm your host, Karen Edwards from askaroofer.com. The Understanding Roof Restoration Podcast dives deep into the topic of restoring roofs. As the popularity of roof restoration continues to grow among building owners and contractors, there are many questions that arise. With a wide variety of roofing systems on existing buildings and many available restoration options, we turn to the experts at Western Colloid to answer your questions on roof restoration. Greg Hlavaty, Hal Leland and the team at Western Colloid have been manufacturing and installing these systems for more than 50 years, and they have seen it all. We will tackle a different topic each month and answer questions submitted by you, our listeners.

Hello and welcome. My name's Karen Edwards and I am with Ask a Roofer and I'm excited to welcome back Greg Hlavaty and Hal Leland for another episode of the Understanding Roof Restoration podcast. Welcome.

Greg:

Thanks for having us.

Hal:

Hello.

Karen Edwards:

Today's topic, I think it's going to be really interesting because we're going to talk about recovering TPO, PVC, EPDM and single ply roofing systems and there's a lot of single ply roofing systems out there. I think we touched on it briefly in our first episode, but I'd like to talk a little bit about the history of single ply roofing, help our listeners understand what it is when it came about and it's popularity.

Greg:

Single ply's, they started to be used back in the 1990s. One of the first strong single applies was EPDM. The other single ply that came about was PVC and Hypalon. Hypalon eventually became a notable failure. Hypalon worked well. They made hypalon coatings back in the nineties. They coated electric wires with hypalon. This has got to be a good product that can weather. The problem is that it worked in the east and some of the less sunny areas, but Hypalon as it moved out west, started having real problems with oxidation.

You could walk on a hypalon roof or look in the parking lot of a aged hypalon roof and it's got white everywhere. It ages very poorly and oxidized. So the hypalon has gone away unless you find a few old ones, especially like I say, out west where we have a lot of direct sunlight. EPDM hung around, but EPDM didn't work well in the west because it's black and black absorbs heat. But it's still used today. Again, not as dominant in the west as it is in the East where they're not as concerned with the cooling of the roof surface.

Hal:

We do still have so many EPDM out west in some old military specifications, I mean specs from back in the 1970s. And they do have white now, so I didn't mention that, but we're still selling it out here and EPDMs working pretty good.

Greg:

So EPDM and the other major single ply that started up and became well known in the nineties was PVC. PVC started out with a lot of failures because the PVC, same thing, or similar technology to what your PVC pipes are made out of and other plastics, very good weather proofer except it becomes brittle with age because it has a plasticizer in it. And the early PVCs, the plasticizer migrated out and became brittle in a relatively short few years of time until the more dominant companies that make PVC developed plasticizers that stayed in the product for the life of the product and kept it flexible instead of getting brittle. And that has become the high quality, high performance product and is used throughout the United States from the northeast to the bottom of the southwest. It works well, but eventually it wears out also like the others. And then came along TPO.

Hal:

Thermoplastic Polyolefin. And the problem with the TPOs, and I've been on TPO roofs, they're 20 years old and they're still performing, but that's one or two of them in the west. They've got a problem and they're on their fourth or fifth generation of formulating that product. And the deal with the TPO, TPO polymer is very inexpensive. Very high performance polymer, but they're having trouble making it consistent or valuable on a sheet. I think it's PVC, it's pigment volume concentration formulating where you've got this much white dirt and this much goop and in the west, the sun's beating on it and it's blowing out all the titan oxide pigment, all the calcium carbonate. If they got a fire package, it blows out all the aluminum tri-hydrate and you're left with the scrim.

Some of these sheets were, this was 15 years ago, they're putting 20 year warranties on these membranes and then four or five years, you're seeing the scrim exposed. And we saw that as a great opportunity to leave that sheet there as a base sheet and then we would put some of our assemblies on it. So in 2010, we went back and we did some testing at FM and we've got five assemblies that come to mind right now that can go over a TPO roof, 10, 15, 20 year warranties.

Greg:

Yeah and TPO is the big player in the marketplace of all types of roofing. I think if you look, go to the NRCA or any of the people that publish the types of roofing that are put on, hot asphalt is drifted down to the small amount. Modified bitumen is still used strongly, but TPO has taken over the market because it can be made in varying thicknesses from a very low-cost economic product to a thicker product. But nevertheless, it still has a lifespan, whether that's a good lifespan or a short lifespan like all the others, it has a lifespan. And when that lifespan is wearing out and you're starting to see scrim, which you do out here in the west, especially near windows or walls because if you have a wall with TPO, it's white. And then so the sun hits the TPO roof directly and it reflects off the wall.

So we've seen many roofs where six feet out around the edge of the roof where there's walls, there's scrim showing and that's because it's getting double or one and a half times the UV that the rest of the roof does. So sometimes, they wear out in spots and in areas and you start seeing the scrim. But nevertheless, we're not saying it's not a good roof and it can't be made into a good roof if it's properly formulated, but it does wear out. And when it does wear out, you're left with, do I tear it off and start over again or can I leave it in place and go over it? And with all of the membranes out there, you can go over it. We have different ways of attacking each one. For a long time, people thought the EPDM, well what are you going to do with EPDM?

It's rubber, it's super stretchy, like a rubber band, like an inner tube, which is kind of what it is. So now I got a EPDM roof that's worn out. What do I do? Depending on what kind of a roof it is, we'll start with EPDM as a matter of fact, and just kind of go over that, because a lot of EPDMs are ballasted. Well if they're ballasted and you take the ballast off, now what have I got? I got a loose membrane laying up there that's not attached. So there's a couple of options to that. We have a system and Hal's gone back to FM and tested over EPDM with our system, our asphalt emulsion, water-based asphalt emulsion, very benign, doesn't attack the EPDM, but it attaches to it fantastically. You can put acrylic on EPDMs but you have to do some special treatments.

But if you put the asphalt emulsion on, it's cleaning it. You put the asphalt emulsion down with membrane polyester fabric and it attaches to it very, very well. And when it does that, that's super stretchy. You're restricting that stretch to the amount that the polyester allows. It's still flexible, still elastomeric, but now you've stabilized it. It's not going to be that loosey, rubbery roof laying there. It's going to have a full attachment of asphalt emulsion polyester fabric. Later, we'll put acrylic surfaces on it with different, depends on the specification and the life expectancy they want.

Karen Edwards:

So question for you before you go too far down the... I'm imagining an EPDM membrane that has the ballast removed, so like you said, it's just a loose membrane. When you put this asphalt emulsion on top of it, does that make the membrane attached to the substrate below it? How do we do that?

Greg:

It doesn't. That's the next step. In some places they'll actually put our membrane on and re-ballast it so our membrane becomes underneath that ballast and stays there. In other cases, when there's an option, they'll attach it. They'll go back and if they have a deck that they can use fasteners on, they'll use proper fastening patterns with the right fasteners for that, whether it's a concrete deck... There are fasteners that will attach to that metal if you're going through insulation to metal, or on a wood deck or what have you, they have different fasteners and you just do the proper fastening pattern for that area and the wind pattern uplift that you want. They put a little protection, peel and stick protection, over each one of the fasteners and then we put our membrane on that. So now it's attached as if it was mechanically attached in the beginning.

So you mechanically attach it or you re-ballast it. And in some cases, we would like to say you can always do an overlay roof, but there's sometimes when you just can't. They can't attach it. They don't want to put ballast back on. They have to go back and start over with something. And in those cases, you can't. But in an amazing amount of cases, many consultants had no idea they could do something with an EPDM roof except re-EPDM it, or a whole new membrane put on there. They had no idea. So there are ways, and we have multiple FM ratings over EPDM and we can give everywhere from a lightweight like house at 5, 10, 15, 20 year assemblies on that.

Hal:

That's a great question on the fastening pattern, because that's what we do mostly, because we can't have that thing flopping around on the roof. So we'll pick a 1-90, 1-120, whatever the wind uplift is necessary in that area and we'll have them attach screws and plates normally.

Greg:

That's EPDM. They make EPDM in the light colors. It's never become really dominant. I don't know if they weather as well. Because I've seen them come and go. For a while there was a lot of white EPDM being made and all of a sudden, it disappeared. Haven't seen it for a while. So they may have pigmentation, stability problems. I'm not in that business, but the black is the dominant that is used and it can be coated and many coating companies will coat EPDM. If it's in good enough shape and you can keep it stable, you can put just a white acrylic coating on it by putting an etching primer... They have primers. They call them primers. They're really just EPDM cleaners. EPDM oxidizes very poorly, even if it's not exposed to sun. If it has had ballast and no sun on it, it's still got a surface oxidation.

There's a lot of black pigment in there that is put in to stop the UV from degrading it. And so you'll have a surface that needs to be cleaned and so they make etching cleaners that will clean all that surface off. And once they do that, there are certain types of acrylic resins. We make one and I'm sure no other manufacturers do, that will adhere to the EPDM and turn it white. So that's a short term. It's not going to re-waterproof it. Your EPDM roof needs to be in a good watertight condition to use just a coating on it.

You can do it. Again, we step up and usually if you're going to spend that much money, you're already spending 50% of the cost of a membrane, so why not put down a polyester scrim in a coating? We use the asphalt emulsion because it has an affinity for EPDM. It sticks to it like glue. And reinforce it with the polyester and then put the white surface coatings on either reinforced or un-reinforced depending on the lifespan they want. So EPDM can be done very well and we have millions of feet of EPDM coated. So that's that one.

Karen Edwards:

Yeah. Let's talk about TPO because as you mentioned, TPO really took off for a while, maybe around the nineties. And there are a lot of TPO roofs out there that are probably nearing the end of their lifespan.

Greg:

Right. There's many of them out there. You see a lot of scrim on it and that scrim is important. Even if we have some where they put solar on many of a certain chain of stores and they put solar on it and the solar dripping on to that TPO over time, has etched away the TPO itself and left voids of resin and only scrim in mid-air, just hanging there. But that scrim's important because it's got some strength. It's not necessarily something you have to throw away. We can use that as a first layer of our system going over it. We have, again, asphalt emulsion loves to stick to the TPO. Other things don't stick as well to TPO. That's well known. TPO doesn't like to have coatings put on it. They'll put silicone on TPO with a special primer.

They'll put your urethane coatings on TPO and those work fairly well. Acrylics can go on TPO, but they need a primer, an acrylic primer, that sticks to TPO. So there's certain resin you have to use to make that bond. With asphalt emulsion, we don't have that. We just clean it, put the asphalt emulsion down, again, similar to the EPDM, and reinforce it with one or more layers depending on life expectancy that they want and with acrylic surfacing. And again, Hal's gone back to FM and got some great ratings, very high ratings with TPO with FM 4470 class 1.

So those can be attacked in multiple ways, but our way is fairly cost effective. Asphalt emulsion isn't expensive, but it loves to stick to TPO, so it's a great way to get more scrim and reinforcement down and waterproofing and then build the UV on top of that with the acrylic and bring it back to a life expectancy equal to the original. And renewable, as we say in all these. When you near the end of our warranty, it's a cleaning maintenance and a re-coat and they're going to get another 10 year warranty out of that. So now they've taken that roof that used to be a throwaway roof and converted it into a sustainable roof that can be kept for multiple cycles.

Karen Edwards:

That's fantastic, because it makes sense for a lot of building owners to consider this as a solution because, and we've talked about this before, there's no tear off so you're saving in labor. You're keeping materials out of the landfill and you're essentially renewing your roof into a watertight condition that comes with a warranty. So I imagine, I don't know the numbers, but I imagine that's a nice cost saving for the building.

Greg:

Right. Right.

Karen Edwards:

This podcast is brought to you by Ask a Roofer and Western Colloid Fluid Applied Roofing. When you're looking for answers for your roof, what better place than askaroofer.com. If you are looking for answers on restoring your commercial, industrial, or low slope roof, look no further than Western Colloid. For over 50 years, they have been bringing old roofs, new life. Together, we're helping contractors, building owners, property managers, architects, engineers and consultants choose the best commercial roofing system. Find Western Colloid today on askaroofer.com.

Greg:

The third major one out there, we talked about Hypalon and Hypalon is not a big factor anymore, but the PVC is and PVC... And may become a bigger factor in keeping it on the roof. We can talk about it at another time. But PVC is a great high performance roof when it's made in the proper formulation. And there's great companies out there that are making PVC roofs but they still come to a lifecycle end. And PVC is something that is a little different. We sell a lot of our asphalt emulsion. We talk about it. But there's a spot we can't use our asphalt emulsion. PVC does have that plasticizer in it and they count on that to keep it flexible so it doesn't get brittle and that the fasteners continue to hold it down and it doesn't crack and break. And so it does that. As it comes to the end of its lifespan, if we put asphalt emulsion on it, sticks to PVC very, very well, but it has a hidden problem there.

And that is that asphalt will suck the plasticizer that's left in that PVC out of it. And by doing that, even though it's buried underneath our membrane, we're going to cause that PVC to become brittle. So asphalt products don't work well on, they don't play friendly with the PVC. They'll suck the plasticizer out and if you suck it out, you're going to get it brittle. Which means even though we'll have a nice water type membrane laying over the top, if it's attached with fasteners, mechanical fasteners, it could get brittle around those and that wind uplift goes away because it'll crack around the fasteners and all that. So in this case, and our FM ratings and our tests that Hal's done are all based on all acrylic.

All acrylic loves to stick to PVC. It sticks to PVC with or without primers. Some companies call for primers. We don't call for a primer because our acrylic sticks to it. It becomes inseparable. You can't peel it off of PVC once it becomes bonded. And then we do different reinforcements, one or two ply's, depending on the life expectancy that they want in a warranty. But it's a great base. We will keep it stable. And not only that, but we lock it. Whatever plasticizer is in there, we're locking it in, so it's in there for many generations to come. Acrylic systems really stick well to that. Again, they put silicones with the right primers and they put other coating systems on there. But our full reinforced membranes, we go with acrylic and reinforcements.

And if you got a PVC that's in moderate shape, there's some companies that will just put a coating on it and an acrylic coating will work well. But it's more of a adding weather ability to it, but not more membrane and not more water tightness. So we step up to adding additional weathering and water tightness equal to the original membrane and then renewable. So all three of them can be done and Hal's gone back and gotten multiple tests, everything from hail to foot traffic to the fire and everything you need to be comfortable re-membraning your single ply's. Don't throw them away.

Karen Edwards:

Yeah, don't throw them away. Keep them out of the landfill. So it sounds like if I was going to recap and highlight a few tips of things to keep in mind when restoring a single ply, what I'm taking away from this one, well we're going to need to look at the condition of the roof. It has to be in a restorable condition. Cleaning is very important, as well as the base. The asphalt emulsion seems to be a wonder product except for PVC. And that's where we're going to have other considerations. So anything else that you would like either a contractor or a building owner to understand when it comes to restoring single play that we didn't cover?

Greg:

One real important thing, and this goes to other roofs also, and we're getting more and more of this, silicone. If you run up and you want to maintain these roofs, these single-ply roofs, they'll often do it with a five gallon bucket of silicone. "Oh you got a low spot there, I can go put some silicone on." It's one thing if you're selling a full silicone system. There are pros and cons to all that. I'm not going to get into that in this. We'll maybe talk about that another day. But you got to have the right primers. You have to have other stuff. But it's now being used as a patch and run. They'll get up there, "Oh yeah, no problem, you got water, you got a split. I can put in silicone." It weathers. It sticks with the proper primer in that. And a lot of guys that are doing patching don't know they need a primer for most of the single ply's and they do.

But once you put that on, especially a building owner, you may condemn your roof to not being able to put on a good maintenance system because nothing sticks to silicone. So if you get enough silicone patches on your roof, you're letting this roofer run around with a five gallon bucket, slopping silicone here and there on the roof to maintain it and keep it going. You may be making that roof unrecoverable. Because nothing's going to stick to it again. Please don't let your contractor, and if you're a contractor, please don't sell that building owner on just patching the silicone. You've taken away so many options that building owner has, and especially economical options where he can do a reinforced coating system on there and save some money. All of a sudden, he can't do that anymore, because he's got silicone patches and the reinforced coating system, nothing's going to stick to it. Very few things stick to silicone. Even silicone often won't stick to silicone. So just be cautious on who and how you let somebody maintain your roof until you're ready to get a full system on it.

Karen Edwards:

It's really, really good advice. And then lastly, I want to mention, because I think it's important to talk about the track record of the fluid applied reinforced roofing systems. You mentioned earlier, you can get a 10 year warranty, a little bit of maintenance and re-coating and you get another 10 year warranty. You guys have been doing this for 50 years, right?

Greg:

Right.

Karen Edwards:

Yeah. So the track record's there. And I just think that that's really important for contractors and building owners to do your homework and to listen to podcasts like this and to visit westerncolloid.com and get the answers. You guys are the experts.

Greg:

Yeah, they can get all the way up to 20 year warranties. They can just pay up front or pay as they go. In other words, you get 10 and then renew. Or we have some systems that you can get full 20 year warranties and you just get that longer lifespan right up front. So it depends on what you're after. And many building owners turn their buildings over and they don't want to pay for a long life lifespan warranty. They sell their buildings every so many years. Others hold them until they fall apart and will still be up there when the building goes.

Karen Edwards:

Excellent. Well, Hal and Greg, I really want to thank you for sharing your wisdom about re-covering and restoring single-ply roofs. I would say next month in our episode, we're going to look at how to address damage to decks when installing a fluid applied roof system and still not having to tear the roof off. So I want to tell everyone to please tune in. You can listen to this podcast wherever you listen to your podcasts, or you can visit westerncolloid.com or askaroofer.com and every episode each month will be up there for your listening pleasure. And don't forget to send in your questions. You can do that through both websites. If you have issues that you want us to talk about or questions that you are being asked or even wondering about, send those in and we will answer those on a podcast in the future. Greg, Hal, thank you so much for being here today.