Fluid-Applied Air and Water Barriers: Expectation vs. Reality (PODCAST)

Welcome to PROTalks, A Podcast by PROSOCO

PROTalks, our new podcast, sets out to tackle the toughest topics in the construction industry every month. In this episode, we discuss fluid-applied air and water barriers. What makes them special and what are some misconceptions in the industry? Join the experts on PROSOCO's technical support team as we discuss this critical construction topic, and be sure to follow the podcast on your favorite podcast distribution service for future episodes. 


Dave Pennington (00:13):

Hi, welcome to ProTalks, the podcast where we take a deep dive into a topic in the construction industry. I'm Dave Pennington, building envelope business unit leader at PROSOCO. And today I'm joined by members of our technical team to discuss fluid-applied air and water barriers and their perception versus reality. I'll let the panel introduce themselves, starting with Guy Long.

Guy Long (00:40):

Thank you, Dave. My name is Guy Long. I'm a building envelope consultant by trade was in the business and a principal with a large building envelope consulting firm out of Atlanta, Georgia. And what I provide for the team is a kind of an overseeing of details and the interfaces between the air barriers and windows and all of the different type components that make up the building. And we also, one of my tasks is to provide some blue beam details to make sure that we're communicating the interface between all of the different building envelope conditions and components. So at this point, that's what I do. And that's what I provide for the team. What about you, Chris? What's your background?

Chris Tobias (01:35):

Yeah, Chris Tobias, I've been in the actually came out of the roofing industry, commercial roofing experience since two, well, 1999 and primarily on the commercial and industrial realm all across the country. And currently what I do with with PROSOCO is I'm a technical building envelope, technical specialist, and I work within the greater Midwest, the Northern Midwest area, working primarily with contractors and, designers, architects, consultants, and really helping them with the details and on-site situations and material training, hands on training with the contractors and helping get the product put on correctly.

Pat Downey (02:18):

I'm Pat Downey, building envelope specialist up in the Pacific Northwest. I cover the whole Western US from Denver to Hawaii from Mexican border through Canada and into Alaska. My background is in the window industry. I've been installing windows selling windows since the early nineties, got into a lot of commercial projects. I specialized in retrofit with windows and doors. And then of course new construction and, Paul, why don't you take it away?

Paul Grahovac (02:48):

Thanks. My name's Paul Grahovac. I started out my professional life as a construction defects trial lawyer, and also spent four years at a DOE national lab, doing environmental law and then six years there doing technology development, transfer commercialization and patent work in support of that. I've been with PROSOCO for 30 years, specializing in the air and water barriers and, give a lot of presentations across the country and, virtually, concerning that, I have a strong focus on standards and requirements applicable to those kind of products and also in, causing to be executed and even developing new tests and, measurements and such relative to that industry

Dave Pennington (03:48):

Fluid applied air barriers, perception versus reality. I'd ask this question to you, Paul, what are fluid applied air barrier systems? What would you call them?

Paul Grahovac (04:01):

Well, they're basically follow-on technology to original means of water and air barriers. And that started with, in fact, it's still the code requirement. It's asphalt impregnated felt paper and that's progressed to spun poly sheeting and then the next progression was to fluid-applied. That basically happened in the early nineties. We started to see some asphaltic, water emulsions, and then in the early two thousands, we see, rubberized asphalt to moving from foundation and, and roof applications onto the above grade vertical backup wall. Also about that time, the exterior insulation finishing system or EIFS EFIS industry adopted, fluid applied water and air barriers in the form of acrylic type technologies.

Dave Pennington (05:07):

Okay. That is a very fast rundown of the history, but thank you, Paul. That's interesting how it all started. I think that, when you look at how it's evolved in the chemistries and technologies out there, you can kind of see it in, in what's available in the market. You know, you mentioned asphalt impregnated coatings that certainly comes from roofing and below grade products below grade waterproofing products that had just evolved when designers and specifiers wanted to start put putting fluids in the wall. So we have that kind of chemistry available, still, asphalt impregnated, coatings, different types. There are some of them are asphalt emulsions, some of them are asphalt, polyurethane blends and then you've seen acrylic coatings that, you know, originally were exterior coatings for buildings have found their way into the wall cavity over the years. And then of course, same thing with silicons, silicone coatings have made it into the air barrier scope of work. And then of course, Silyl-Terminated Polyether coatings have been advanced to be included into the air barrier scope of work. And so all of those different chemistries certainly provide, different, you know, things that they can do.

Guy Long (06:40):


Dave Pennington (06:41):

Workability, you know, performance, everything, just makes it, they, they all have better different attributes. So,

Guy Long (06:49):

Well, the key with, with what we provide at this point in time is the STPE technology provides the ability to apply subs materials and air barrier products and systems when substrates are wet. And it kind of goes to construction from the standpoint that recognizing that we don't build in laboratory conditions and substrates do take on copious amounts of water. So in, in the reality of the old technology that we're accustomed to seeing, with this new technology, we provide the ability to simply wipe substrates off and continue to apply material saving all kinds of strategic time for the general contractor in his quest to get the project done and in, and under time, by, by providing that ability to put it on when substrates are wet very important. But again, I, I go back to, from the, the standpoint of permeability and non permeability, we don't have the ability to tent every building and protect it from the weather.

Guy Long (08:10):

And what we find is that the zero perm systems that are on the market initially can be problematic. And what we're doing is locking in moisture in the substrates, hoping, and depending upon the HVAC systems to pull the moisture out of the system, the reality is it doesn't do it. And that's why we feel very, very comfortable in making recommendations with regards to using a permeable or open system that allows the substrate through diffusion the opportunity to dry. And that's the key to the performance of any air barrier that it allows the substrate to dry. Once it's dry, then we're in good shape because now we prevent the liquid moisture from coming into the system.

Paul Grahovac (09:01):

That's right. And I wanted to put the STPE in the historical sequence or context I was talking about. For 50 years, that chemistry has been the leading construction sealant and adhesive in Japan, where it was invented. And it's finding its way into the European market in that application as well as into the US market. But as far as its use as a coating that was pioneered by the people that provided the early versions of the technology we commercialized. They started using it as an air and water barrier coating in 2005 and every five years since then, have had forensic architects evaluate the continued functionality of that material and report successfully on that.

Dave Pennington (10:00):

Thank you, Paul. Well, Guy, you know, going back to the perm and non-perm, advantages of the coating permeability and the non permeability, we still see a lot of people wanting to use nonpermeable products. What do you think is driving that? I mean, to me, it seems very, difficult in that you're using that expecting that there's no moisture in your wall. You're gonna keep moisture out. It's never gonna be in there, but everybody knows that, you know, construction materials sit on a job, they get rained on, they get wet, they get erected and they get covered up. And you've got moisture in that wall, not to mention the moisture drive that comes from the interior of the building, you know, from showers and sinks and faucets and people breathing, you know, I mean, that's kind of seems counterintuitive, but what is your thought?

Guy Long (11:00):

Well, it's, it's very true. And what we're finding is, and that all of our tech team deals with this on a day-to-day basis, recognizing that not all of the architectural community understands that things have to be dry over time. And we don't have the luxury when we provide a zero perm product on the wall for an air barrier, when the walls are saturated as opposed to having the ability to let it dry with a permeable product. We do see applications with regards to a zero perm system with the application over refrigerated buildings, food stuffs. A lot of the times you're going to find that industrial type, hospital type applications will be using zero perm, but they have a very, very intricate HVAC system that they control very, very intimately and maintaining humidity levels, and such as that because of operating room conditions that they have to deal with, along with environmental, microbial growth, all those things that they have to deal with. So it's really handled, not necessarily just from a zero-perm air barrier system, it's more, in conjunction with the HVAC systems and their intricacies to, to maintain a comfort level within the structure.

Dave Pennington (12:39):

Yeah. Thank you. Well, what do you guys think are some of the strengths and weaknesses of fluid applieds out there? Pat, you have a history with this. What are your thoughts on that?

Pat Downey (12:51):

Yeah. Basically I was introduced to the fluid-applied back in '06. You know, we build in real-world conditions and to kind of jump on what Guy said about peel-and-sticks and nonpermeable, you have a rainy day, a rainy week, and then you have one dry day. The general contractor wants to keep the schedule and wants you to put the peel-and-stick on. When I was introduced to a breathable liquid flashing for windows, that was a game-changer. It did several things. One, it was easy to apply to the rough opening. And then depending on your weather barrier air barrier, whether it's fluid applied, if you have a fluid applied air barrier, then it becomes monolithic. The fluid applied makes it much easier to detail around through-wall penetration, pipes, electrical boxes, you name it. Using a peel and stick in that area was rough.

Pat Downey (13:46):

And again, back to the, the nonpermeable peel and sticks in rough openings. Have my crews ever installed nonpermeable peel and sticks on a damp surface? I cannot confirm nor deny that, but it does happen. And that's where we have a lot of restoration issues. Depending on your, your fluid-applied chemistry, one of the negatives is that, you know, the weather, again, it's out there, you're on a CMU block, wall system and they haven't capped the top. Well, there's certain weather barriers you cannot put on that substrate or damp wood. The other thing is that we've had people where they, one day they put on their acrylic air barrier and the next day it's all washed off and on the ground because it can't withstand rain hitting it. There are some, the PROSOCO products can withstand rain immediately once it's put on there. Anybody else got anything to add?

Chris Tobias (14:44):

Yeah, just kind of jumping on what you were saying, Pat, about detailing and getting things, water tight, you know, coming out of the roofing industry have been around the roofing since '99. And one of the most important things is getting things, watertight, right? You can't have water in the building. And, so details become ultimately important. And we used to often would say devils in the details. And, you know, when you think about why we talking about roofing, well, the roof and the wall meet. So that roof to wall transition is, is critical, not only from a standpoint of water intrusion, but also continuity of the air barrier and, you know, just dealing with fluid-applieds and the odd geometries that exist at those roof to wall transition details, fluid-applies really really adhere themselves to working around and make it easier to install in those various geometries.

Chris Tobias (15:35):

So, you know, when you think about how do we, how do, how do we get contractors? How do we construct these details? And then how do we make them dry and airtight, you know, fluid applieds really do a great job with, with regard to that, not, not to mention some fluid-applieds have a tremendous amount of compatibility with a variety of materials. So, you know, compatibility is a big issue and there's certain materials, certain fluid-applieds, STPE, come to think of it is really, a great product to be compatible with a variety of materials as they marry with the roofing systems.

Pat Downey (16:11):

Yeah. And to add to that, there's no lapping, it's monolithic. So you can have one crew member starting at the top, the other at the bottom or east elevation to south elevation, and they can marry up with the liquid applied. If you have a peel and stick building paper if they're not lapping properly that's gonna cause issues as well as if there's a change where through wall penetration is going through. If they have to move it over six inches to a foot fluid applied is easier to detail around and to fix those issues.

Dave Pennington (16:44):

Yeah. Excellent. Thank you guys. Well, those are some great attributes strengths to the product but, what are your thoughts on some weaknesses for a fluid applied?

Paul Grahovac (16:56):

Well, it's not really a weakness. I, I was gonna mention it's a perceived issue and that's cost. Fluid applied materials only tends to cost more than sheet good, building wrap. I don't know about peel and stick. I think it might be the other way around with that. I, I don't have that familiarity, but comparing it to spun polyolefin sheet wrap, I believe the fluid-applied the material only does cost more. But it's the speed of construction that has to be taken account. And that's why we have contractors going to architects on projects and asking that the fluid applied be substituted for the sheet goods, because even though the material costs more money for the material, by the time you figure in the labor, and particularly if you want a high quality air barrier installation, that's going to actually provide the limitation of air leakage that you're seeking. , it it's, it's more cost effective to do it with a fluid applied.

Dave Pennington (18:07):


Pat Downey (18:07):

Yeah. It makes everything intimately bonded to the substrate with the fluid applied, the penetrations and all that, where building paper is just flapping in the air.

Dave Pennington (18:17):

Yeah. Well, you know, a comment on building paper that, that one always amazes me because it's, obviously it was the first one first product to the air barrier industry and highly specified and used all over the place that the perception is that it's inexpensive, but the perception of expense is for those guys that are putting it down, they, they drop it down the building and then they hit it with a slap stapler and they move on, but people don't realize that that is not the proper way to install it. And if you don't install it properly based on their almost 200 page installation manual, you void the warranty. So if that's the way you're gonna do it, yeah, it's gonna be cheap, but it's not gonna have a warranty behind it, and it's gonna be a problem. And you're gonna be looking to fix that building.

Dave Pennington (19:01):

In a handful of years. If you do it properly, that pricing goes up well past the, the way fluids go , per square foot on a job. So you know, using the right button caps for the fasteners, spacing them out properly using the right flashing or detailing in the rough opening rather than cutting an X and bending it in there and slapping a window in it. I think that, that the people that have been in this industry for a while, see that as a massive weakness of that system, because it most never ever gets installed properly. I see it installed properly. And I know that that price is a fair price, but when you see it done terribly bad, somebody's just getting a bad product. And it's hard to look at when you drive down the road, seeing those flags flying in the air, but what are some other weaknesses about fluids? We didn't really talk about it, but I think that's when you start dialing in, on the chemistries guys. Right. I mean you know, some, some of them have weaknesses where they can't be used in wet weather, some of them, you know, on like that. Pat, what are some of your thoughts on that?

Pat Downey (20:12):

Yeah, temperature is an issue. I do a lot of projects up in the mountains and the Rockies, and they're switching to fluid applied cuz they have issues with the building paper and some chemistries can't be put on below freezing or even below 40 degrees. If you put 'em on there, they won't cure properly. Especially the water based products some of the acrylics and emulsions. There are products, the moisture cured, that can be installed down to freezing level some below that. You just need to be able to introduce moisture. The other issues again, the project the schedule one of the handicaps is up here in the Northwest. It's been raining quite a bit. We had one sunny day. And so if someone put on certain chemistries acrylics the other day went was sunny, but then it rained really hard. The next day they're gonna wash off. So you gotta be careful of who's driving. Who's putting the product on, they need to put the product on the proper substrate at the proper time. There's other chemistries like the STP, which is not gonna be affected by that. Once you put our products on it's immediately waterproof, so it can be hit by rain. It's not gonna wash off. So you've gotta be careful when you apply products, you gotta know the chemistries, you gotta know the pros and cons of each one.

Guy Long (21:39):

I think the other thing Pat, that we haven't kind of been the, or actually it's been the gorilla in the room, talks about thin mil versus thick mil. And one of the things that we find is that comments of people that have used the older technologies believe that the thicker mil provides a better system in that it's a lot more forgiving. The reality is that when they talk about having a thick mil product, the chances of it being put on at the correct thickness is slim to none. The key here with regards to a thin mil system is that it's thick at the locations that need to be thick such as at our board joints, at our interface conditions that we have and see significant movement. We have the capability of providing the millage that's required to take on those movement conditions without having to substitute reinforcing mesh.

Guy Long (22:49):

And such as that, the key with the thin mil systems are that they can provide much more suitable solutions to providing the ability for things to move, as we all know, take place in every building every day.

Dave Pennington (23:08):

Yeah. I agree with you Guy. I think that's a, that's a perception versus reality kind of deal. And you know, the thing that kind of bothers me about using the thin mil versus thick mil terminology is just that, you know, just the way that sounds. I mean, if I didn't know anything, I'd say, well, I want the thick stuff, you know, I want, I want the beefy stuff, right? But we're thick where it counts with our chemistry, and the other thing to kind of add to that is that we detail with our STPE products. So we have basically

Dave Pennington (23:44):

A monolithic coating, they all cure together as one product. Our systems, aren't a Frankenstein of systems like some of these others where you have an asphalt based coating going over a different kind of chemistry in the detail with peel and stick in the window and, some sort of other sealant involved. I mean we're talking about, you know, monolithic coating versus all these others. But I would prefer, we just said fluid applied versus non-flu applied or, you know, peel and stick or whatever. But I agree that's the perception versus reality, we're thick where it counts at the transitions and the penetrations. Another thing in perception versus reality realm is just the contractor's resistance to change. You know, these guys have been using thick mils and thick mil type coatings and peel and stick air barrier membranes for a long time.

Dave Pennington (24:50):

They know where the pricing is at. It's easy to bid, they just plug the number and they move on down the road and do the job. So it's critical to educate guys and show 'em how to use our products. Show 'em how much faster it is to use, show 'em how much easier it is to use. And, you know, you can work on days where you couldn't work with peel and sticks or, or asphalt based products because it hasn't If it rains on a Monday and it hasn't dried out and you gotta wait three days for those products to go down, I mean, you can go to work with our products.

Guy Long (25:25):

You know, Dave, one of the other things with peel-and-sticks, what you find is, I'm coming from a forensic background in looking at building failures. A lot of the time the adhesive nature of the peel-and-stick gives up the ghost a few years down the road, unless it's mechanically attached. The nice thing about these monolithic thin mil applications is that it's bonded structurally to the substrate, which makes all the difference in the world. I don't have to worry about in 10 years, did that peel and stick adhesive stay in place or did it allow to stay in place more specifically around the perimeter of windows? That's where that was used quite extensively. And as a result of that, what we have found at through wall flashings, at floor level interfaces, those kinds of things, most of the time, unless mechanically attached, we find that those through wall flashings and peel and sticks are at the bottom of the wall and nonfunctioning. And the folks in the building are now suffering from outdoor air, getting in through those locations, moisture related conditions, the microbial growth wetting out of the substrates on the interior.

Guy Long (26:53):

It's all part of understanding. You gotta look at it 10 years, 15, 20 years down the road. Most of these buildings are, are built for 50, 75, a hundred year use. And if you've got a product that every 10 years you gotta replace, because the adhesive quality of the peel and stick gives up the ghost. Well, then you're in trouble. So that's some of the things that you have to think about is from a long term perspective.

Dave Pennington (27:22):

Yeah, absolutely Guy. I'm down here in Texas and I've seen a lot of peel and stick membranes at the base of a wall.

Dave Pennington (27:29):

<laugh> It gets hot. <laugh> well, let's I appreciate everybody's input. Let's kind of wrap this up. You know, I think we all agree fluid applied air barriers are here to stay. They, they just are easier to work with. You can do so much more with irregular geometries in a small space. You know, the the technologies that are up out there right now have been upgraded over the years and, and there's no telling how, how much further they can be upgraded, but they provide better chemistries when they are that gives you more latitude to work and solve problems. And then, you know, we all agree that educating people on our products, doing demonstrations and talking about it helps contractors help specifiers. You know a lot of specifiers out there think that just because it's thin, they don't know if it's thick enough.

Dave Pennington (28:30):

That's why they like the thick mills, but, you know, you gotta look at the jobs and you gotta know what you're looking for, you know? And then the bottom line is the industry needs more involvement from manufacturers, you know, no matter what product you're gonna use I think it's imperative that manufacturers need to be involved with the contractors so that the guys know what they're doing. When they put material on the wall, they need to be involved with the specifiers, making sure the right products are being used on the job and they need to be involved to the point where they're helping with details with the architect or with shop drawings when the job's underway, because every project has its own project specific details and, and the manufacturer needs to weigh in on that. You can't just sell a product, put it on a shelf and clap your hands and say, good luck guys. You gotta be in there with 'em. So I think that's a big part of what the industry is needing these days as well. So anybody else have anything to say?

Dave Pennington (29:40):

I think that was a great conversation about fluid-applied air barriers-perception versus reality. Thank you guys.


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