Waterproofing, Window and Door Flashings

John Babun – Sika Corporation

  • What are the largest challenges you see right now pertaining to window and door flashings?
  • What are the benefits of liquid applied flashings?
  • What are the benefits of a cementitious waterproofing for windows and doors?
  • Is one flashing appropriate for all applications?

About The Everything Building Envelope Podcast:      Everything Building Envelope℠ is a dedicated podcast and video forum for understanding the building envelope. Our podcast series discusses current trends and issues that contractors, developers and building owners have to deal with related to pre and post construction. Our series touches on various topics related to water infiltration, litigation and construction methods related to the building envelope.


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Paul: Hello everyone, welcome back to the Everything Building Envelope podcast. I have a really interesting guest today, John Babun, with Sika, and John thanks for coming on the show today.

John: Great to be here.

Paul: So we’re going to be talking flashings for windows and doors, which is a pretty interesting topic because it’s changed a lot over the last five, 10 years, we used to cut up pieces of metal and try and piece them together and poke holes in them with fasteners and have them not leak, and now there’s a whole new family of fluid-applied materials that really make things…they’re just way better and a lot easier to do. But before we get into that, John, would you mind telling the audience a little bit about yourself?

John: Sure. I started in the industry as a regional manager for one of the largest waterproofing suppliers in Florida. I was there for about a total of 10 years, from there I started my own waterproofing and window and door installation company. And I had that for about seven years and then based on some things that ended up changing, we ended up closing that company and I’ve been with Sika now for a total of about three years. And now I’m the district manager for Sika Corporation for the Commercial Refurbishment, Ceiling and Bonding Division, as what we call it, for Florida, Georgia, Alabama and The Caribbean.

Paul: Right, I know Sika is a name I think that most listeners are familiar with, but in case they’re some that aren’t, could you tell us a little bit about Sika also?

John: I sure can. Sika is a global company, we’ve been around for about 110 years. We’re made up of about seven different target markets, and basically…I had mentioned the Commercial Refurbishment, Ceiling and Bonding, that’s one target market that deals basically with concrete repair and sealants and waterproofing products.

And then we also have a concrete division that deals with admixtures, and concrete itself. And we have a specialty flooring division which deals with interior flooring and epoxy flooring and hospital floors and all kinds of special floors. We also have a roofing division called Sika Sarnafil, and they deal with PVC roofs. And we have recently acquired L. M. Scofield, so they’re now called Sika Scofield, and then we also have Sika Greenstreak, and Sika Greenstreak is a below grade waterproofing. So basically what it allows us to do is as a company, we can single source projects really basically from the bottom-up, right, from below grade, all the way up, outside the windows, inside and up to the roof.

Paul: So like what’s the advantage of being able to single source from one manufacturer from, as you said, from in the ground right up to the roof?

John: Probably the largest advantage of a single source is we know what is compatible with what, and what adheres to what, so in other words some of the most vulnerable areas of a building envelope are the connections, from one waterproofing piece to another waterproofing piece. And when you’re dealing with multiple manufacturers, often times you run into the situation where one might not be compatible with another. And if there is a failure, you obviously run into the situation where you have the blame game, right, everyone pointing the fingers at each other.

So frankly, the largest benefit of a single source is if you use a project that goes Sika from ground-up and there is a problem on that project, there’s one call to make and one company to bring to the table. But hopefully, all the homework’s been done ahead of time and you won’t have that issue because we already know again what’s compatible with what works where. So, you avoid all those situations in the future.

Paul: Yeah, that’s well said, you know, the other thing that we run across at GCI Consultants on projects is where even if things aren’t compatible, we’ve had manufacturers. I’m not saying Sika is one of them because I’m certainly not thinking of Sika when I say this, where they basically have warranty exclusions if other materials are used adjacent to theirs, which creates problems, especially if you find out about it after you’ve already halfway through the project. So we’re gonna talk about window flashing, as we did in my little presentation when we started, about the evolution of flashings, and you agree with that, I assume?

John: Yes, yes.

Paul: Yeah, it’s really great. The fluid applied materials have really helped, from our perspective, as you know, our consultants and quality control side has really helped simplify things and helped get better results. You can…it’s a lot easier to inspect, you don’t have as much blind penetrations and putting holes in things as you used to. And you can really just tell…it’s just better technology and you can tell what you’re getting. So, and what are some of the largest challenges you see right now pertaining to window and door flashing?

John: Well, what I would say is, and I echo your comments about flashings, are really a good thing for our industry. But in that being said, as it’s become, as it’s been flourishing and there’s more and more flashings out there, more and more manufacturers are coming out with product that could be used potentially as flashings. And so there seems to be kind of a wholesale confusion almost in the entire marketplace, about flashings.

So, I mean, I would say when it comes to the challenges, the largest challenges I see personally is just a complete…the wholesale lack of education in our industry about flashings in general, and that really gets into different things, from code requirement to application techniques, just to the technologies themselves of the flashings, which technology really should be used where, you know, and how? I would say one of the biggest areas I see an issue with is the application techniques of flashings.

Since there is such a lack of education in the industry, and that’s why it’s so important that I think there is a consultant involved in a project, that is educated and understands flashings, because I see it far too often where a contractor just applies a waterproofing product around a window and door opening. And since no one on the job really understands the requirements of a flashing or the application techniques of a flashing, they may think that window or door has been properly flashed when indeed it hasn’t, because the manufacturer’s instructions or the manufacturer’s recommendations were not followed.

That lack of education in the application of flashing is a big deal, as well as the technology, you know, I know we had mentioned a little while ago compatibility, but I would say, we’re seeing significant failures in the marketplace from other manufacturers of flashings and sealants, only because what’s happening is compatibility between a parameter seal and a flashing may or may not be known.

Usually you have different trades applying…you may have a waterproofer applying the flashing and then a window installer installing the parameters, and if they’re not working together and if the specifications aren’t calling for two products that are compatible, what we’re finding is people are installing flashings that…actually there are some flashings that have an alcohol cure and as you know, Paul, that alcohol is a nemesis of sealants, right?

It’ll inhibit the cure of polyurethane-type grade, silicones, whatever it may be. And so we’ve seen many situations where people are installing these waterproofing products that have alcohol cure and then they’re caulking to them whilst those products are curing, so it inhibits the cure of the parameter seal. And so now you have a wholesale failure on the entire project of sealant that just never cures. And so a lot of pain and financial loss can certainly be averted if the proper education is there and the flashing and the sealant on a building.

Paul: And it’s a case of dotting your Is and crossing your Ts sometimes, what’s funny is when you were talking about this I was just thinking to myself, you know, there’s one other challenge that we see out there, we have clients who say, “Why the hell do I have to use this stuff at all? It’s, you know, it’s costing me a lot of money.” And we’ve had to go through, in some cases, mockup testing with and without and what not to demonstrate the need, and it is a standard of care or a state of the art in the industry now to use flashings, fluid applied, typically around window and door openings, where it used to be nobody put anything in there. And, you know, we’re building better buildings now obviously.

You were talking about failure, so what are some of the manifestations that you see in failures? I mean, one that comes to mind obviously is something doesn’t stick to something else, are there other things that you’ve seen out there, a failure [crosstalk] proper materials were used?

John: For sure, yup, and great question, probably, I would say the two largest failures we see are the…as I mentioned earlier, the incompatible parameter sealant with the flashing, so you have sealant failure and obviously water infiltration there. The second failure we see is often times Stucco is applied on top of these liquid-applied flashings. And there’s usually a special method to make sure that the Stucco adheres to the flashing, and if that method is not followed you can get a Stucco failure, to where the Stucco would delaminate because Stucco is just not gonna adhere all by itself to a liquid-applied flashing. So we certainly see that, those would be the top two failure issues we see.

Paul: What does Sika do with their application to make sure or to facilitate the Stucco bonding to it?

John: Well we have really two different options when it comes to flashings for Stucco application. For instance, our liquid-applied flashing is a product that you simply, after you spread it out, and it’s called the Sikaflex-102 EverFlash, but you spread it out and you broadcast sand into it, to refusal. The benefit of Sika’s liquid-applied flashing is that it’s a little heavier bodied than most on the market. And so albeit some other manufacturers also will recommend sanding to refusal, the issue we see over there is that there’s just not enough body, there’s not enough viscosity to their material to hold the sand. And so what happens is the sand itself releases from the flashing, and so again you have the Stucco failure.

So with the Sika product, there’s enough body that you truly can saturate the flashing with sand, usually it’s an oven dried silica sand, and then we have no issues whatsoever of Stucco adhering to it.

The other option we have is we do have a flexible cementitious waterproofing, and I do wanna emphasize the flexible because that’s very important when it comes to especially CMU, right? You wouldn’t be using a flexible cementitious waterproofing on a wood frame building obviously, but if you are dealing with CMU it’s very important that the cementitious product you use, if you are using one, is flexible and able to take some sort of, well, flex. But the benefit of that is you don’t have to do anything to it. It’s simply brush-applied around the entire window or door opening and, you know, onto the face of the CMU, and when the Stucco contractor comes along, you know, and nobody has to do anything special to it, they just simply install their Stucco as they would in a normal application.

Paul: Is one…is liquid-applied and cementitious, well, how do they compare pricewise, and one more or less than the other?

John: Yeah, you’re gonna have the…cementitious is gonna be less expensive than the liquid-applied. But you have…you always have your pros and cons, right, you’ll have your benefits of one over the other. And the benefit of a liquid-applied, obviously, is it’s seamless, but probably the biggest benefit of the liquid-applied is that you’re able, with ours, you can caulk to it with the parameter seal as quickly as two hours after application.

So for those projects that, you know, they’re taking out a window, they have to flash the opening, put in a new window and then caulk the parameter, and it doesn’t matter if you’re using…we know with our technology, with our liquid-applied flashing, if you’re using any Sika, either urethane or a Sika hybrid or a Sika silicone, all three of those technologies will adhere and are fully compatible to our liquid-applied flashing, as quickly as two hours after the flashing is installed.

So if you’re in a fast track project and you wanna get a window in and out caulked, you know, flashed and caulked, certainly liquid-applied would be the way to go. When it comes to the cementitious, the flexible cementitious, and the benefit with that product again is it’s a little less expensive than the liquid-applied, but you do need a little bit more time. So in other words after you apply the cementitious to a window or door opening, we don’t want the bucks installed or any caulking to it for three days. So you need to allow that cementitious product to cure.

So that’s where often times what we’ll see is in a new construction situation where, you know, they just need to waterproof these window openings and they’re gonna come back a few days later and install the bucks and then the windows, that’s perfectly fine and works out very well. But, you know, again when you’re in a fast track project and you don’t have three days to wait before you can install the bucks and the windows, then you just go with a liquid-applied flashing.

Paul: That’s interesting, I was talking to a contractor that we worked with on a very large high-rise building a few weeks ago, maybe a month ago, that was telling me that they had a issue, it was a different manufacturer, with the broadcasting the sand into the liquid-applied material, and the sand, you know, the workmanship wasn’t good apparently, and he was frustrated because he didn’t really have any way to co-lease it. You know, you’ve got a very large, I won’t tell how many storeys, I don’t wanna give it away, but a very high building, and we can’t watch installers the whole time, you just can’t do it. You can spot check, and things like that, and they ended up with an issue with delaminating Stucco, but on the window opening.

So I think what I’m gonna do when we finish this podcast is send him an advance copy so he can hear about the cementitious, because that was a new construction project where he would have time for that.

Interesting, with the fast cure time on the liquid-applied, you know, we have projects that we have selected waterproofing for that very reason, we did a really large out on Miami Beach that was an existing building, and this hotel, it wasn’t occupied because it was a major, major renovation, but a window had to come out and go back in the same day and you had to have a fast curing material in order to make that happen. So I think that’s something that probably comes up more than people would think and that it’s really important.

John: Yup, I agree and you know, Paul, as you mentioned earlier, what we can do, the best thing we can do is alleviate the human error, right? There are…it is human. We have to understand that this industry, you know, sometimes the application of products, and I’m talking more specifically to sand, right, sanding these liquid-applied flashings, you know, they may sand it better Tuesday, Wednesday and Thursday, you know, because Mondays the guys might be dragging and Fridays the guys might wanna be out of there. This is still…there’s human touch to standing the material. So it is important to recognize that, you know, maybe this project, if you have the time, you know, it’s better to keep it as simple as possible and as easy as possible.

Now that being said, you know, one thing I do wanna mention about our liquid-applied flashing, is we did keep that keep-it-simple mentality in mind for the workers, you know, in that our flashing is used for everything, when it comes to that window opening.

So to extrapolate on that, you know, when you’re installing a liquid-applied sealant, you need to caulk all the nineties, you need to…if there’s any cracks, you need to caulk all the cracks and then you install your liquid-applied flashing. And then when they put the buck on, they need to embed the buck in a sealant, and then they need to caulk the buck and caulk all the nineties and then flash the buck.

Now there’s many manufacturers have multiple products to do all those things. The benefit of the Sika-102 EverFlash is you use that product for everything, so you’re not mixing and matching. There’s not a chance of your guy picking up the wrong material and caulking the ninety or the crack with the wrong one, you know, or vice versa, all right? So it is a very user-friendly product or keep-it-simple product, with the exception of you do need to sand it, if you’re gonna put Stucco over it.

Paul: So I’m a huge fan of simple and easy, having seen so many projects and so many systems, right, when things aren’t simple and easy they don’t always go well. And the easier the better, I think, so using one material as opposed to two or three…if you’ve got multiple materials and a lot of workmanship involved, you’re almost guaranteed that you’re gonna have a problem, I think, maybe not but generally that seems to be the way things end up.

And this is such a critical area with, you know, keeping water out of the building, and Stucco delamination is another huge issue, and as buildings are completed, Stucco and water infiltration are probably two of the biggest drivers of post-construction claims. So it’s vitally important to really pay attention to what you’re using, how you’re doing it, and having a…I guess a reasonable plan to get it done probably.

Because, even if, you know, you’re a consultant on a job like our firm, there’s only so much we can do. We can’t sit there with the crew and watch every single opening be applied, you know, we can spot check, but you can’t keep up with it all. So it’s really that idea, good system, good QC program and easier or your…give you the best chance for success.

John: Right, I agree, and understanding the limitations of the products you’re using, as well. And, you know, and talking about the failures, one thing I didn’t mention is exactly that, the limitations of the products. Because we do find another area that we see failures is simply someone may have installed a liquid-applied flashing at the time properly. However, there is some liquid-applied flashings that are not UV-stable. And so if there’s exposed to the UV for, you know, two weeks, 30 days, any length of time, that product has already started to break down and so then when you do come in and put in the window and install the primer seal, you have an issue, because now you’re already dealing with either a chalky product or a situation where the UV has broken the product down.

So understanding the limitations of the products that you’re dealing and really using them to fit into the true schedule of the project is an absolutely critical topic, as well.

Paul: So you’re talking about UV-stable, I’m guessing your products are UV-stable?

John: Yes, both the liquid-applied and the cementitious can be exposed without issue to UV for any length of time. We really don’t have any issue. The only thing that would happen with the liquid-applied because it is white in color, is it may tend to yellow, you know, if it’s out there for six months or nine months, it might start to get a little yellow, but that’s not affecting the performance of the product nor is it affecting the ability for the parameter sealant to adhere to the product, assuming it’s a Sika parameter sealant. And the cementitious obviously we have no issues with that being exposed, as well.

Paul: It’s made me think of something else, what type of surface preparation is needed before you apply these materials to the raw, rough opening?

John: The biggest thing is just clean and dry, and you really just don’t want any lose weight inside it and you wanna dry , unless you’re installing the cementitious. The cementitious you would actually SSD, or Saturated Surface Dry is what we call it, you would moisten the concrete first and then install the cementitious. But for a liquid-applied it needs to be clean, it needs to be dry, there are a couple of things that, you know, again, if there’s cracks you wanna detail the cracks. Sometimes there may be holes, for instance there’s some projects we do when they’re carrying out a window and they pull a fastener out and now you have a hole the size of, you know, half a golf ball there.

Typically you would wanna fill that in before doing the liquid-applied flashing. Now Sika we do have products, we have very first-tier epoxy products that you would just…it shot out of a tube and you could fill a hole like that and it cures immediately, so you can just keep moving forward with it. And of course you maintain a single source warranty on the hole opening. But the most important factors are clean and dry if you’re dealing with liquid-applied.

Paul: And you mentioned warranty, what are the warranties that come with these products?

John: Well with our product we actually give a system warranty if they use both our flashing, and you use either a liquid-applied flashing or the cementitious for that matter. And one of our sealants is the parameter seal. We’ll provide a five-year window opening warranty, window opening, hard waterproofing warranty as a system. So that covers both the parameter seal and the flashing. Now there’s times that, for instance if someone uses our hybrid, our hybrid sealant, which is the SikaHyflex 150 LM, we can give a 10 year warranty on the parameter seal, and if they use one of our silicones, like the Sikasil-295, we can give a 20 year. So basically what you’re looking at is a minimum of a five-year system warranty and it could go higher than that based on the parameter sealant that’s…

Paul: And so if you’ve got this stuff on the wall with a five-year warranty and you use a 20 year sealant, it sounds like, you know, there’s a gap there, but I guess what…the reality is that obviously it lasts a lot longer than five years so if you can get through the first five years then you’re probably good to go for quite a while I would guess.

John: Absolutely, yup, you’re right.

Paul: So we talked a lot, you know, the variables with the pros and the cons with each of the…liquid applied and cementitious, can you use either one of them in all applications or what…how do you pick one or the other, I guess?

John: You know, the only one that…if you needed to use one for all applications it would be the liquid-applied and that’s because that can coat the window opening as well as the window buck, and you know, you’re fine with that. When you do use our flexible cementitious, you’re using the flexible cementitious which is the SikaTop Seal-107 around the window opening, but then the buck itself gets flashed with the liquid-applied, the 102 EverFlash. So when you’re using the cementitious it’s a combination of the liquid applied and the cementitious, and when you’re using the liquid applied, the 102, you’re only using that. So I guess if you were to use just one product, you certainly can do that with the 102 EverFlash.

Paul: And then if you were using, if your substrate was not masonry, you know, it was wood frame or gypsum sheathing or something like that then I’m guessing that the liquid-applied would be the way to go there?

John: Yes, yes, as a matter of fact the other benefit of a liquid applied is it does go over so many different…a variety of surfaces, a variety of substrates. So when you are dealing with whatever it may be, it may be wood frame and chip wood, or whatever the other substrate may be, you can certainly do that. All you do is you caulk the seams, again with the 102 EverFlash, so you’re not using multiple products, you use that product itself to caulk all the seams, everywhere there’s a connection. And then you coat the whole area with the EverFlash, so certainly when you’re dealing with multiple substrates that’s the product to go with.

Paul: So, obvious this material has really come a long way, or window flashing in general has come a long way. As I said in the beginning, I’m aging myself, but I remember back to the days when, before you even saw the window you’d have to take a piece of sheet metal and bend it and break it and put it in and seal it and it was just a mess. And it was so hard to do it correctly, and then if you had to put fasteners in, you would have, you know, you’re basically putting holes in it, and the fluid applied materials have really, really upped the game and helped the technology tremendously, so it’s great to see and it sounds like Sika has some really good solutions for our people to use that utilize the technology, basically.

John: Yup, we sure…and the other benefit of the flashing is you’re protecting the bond line of that parameter seal. You know, I mean, we see it far too often where depending on the sealant technology used around that parameter of the window opening, but for instance when it’s two…say a concrete block, it may adhere perfectly fine during the course of the project, say there’s no flashing used, that parameter sealant may adhere fine to the block.

But if there’s a failure and say there’s a…let’s say it’s Stucco and the Stucco cracks and that block gets saturated, and that sealant bond line now is essentially saturated for a long period of time, that’s sealant can lose adhesion to that concrete block, and now you have a failure, a water infiltration failure. So that’s one of the reasons I’m a big fan of flashings, is because you’re truly protecting the bond line of the sealant, because if for whatever reason water ever does get behind that flashing, and it will never get through the flashing, so you’re protected.

You’ve the protected the bond line of the sealant, which is obviously the most critical part of keeping water out of your building. So, you know, I would love to see flashings used everywhere, it’s still like pulling teeth sometimes to have people use them because they do see the extra cost, but it’s really such a long-term value for a building.

Paul: Yeah, I’m with you a 100% on that. I know you can do it, I know it’s a manufacturer’s recommendations but I’ve never liked applying sealant material directly to masonry, it just doesn’t seem like it would be an ideal bonding surface, so if you can prep that surface and then have a better material to bond it to, I’m a fan.

John: I agree.

Paul: So really interesting, really important for the listeners, I think also, to hear the reasons to use these new technology, flashing materials and as I say we’re building better buildings now and this is one of the big advances that I’ve seen over the last five or 10 years and it’s becoming a lot more widespread, and it’s really good stuff. So really interesting John, thanks so much for coming on today.

John: Thanks for having me, I appreciate it.

Paul: I’d love to get you back for another topic, because this is really interesting stuff. I know that the listeners really, really enjoy it as well, so…

John: Anytime, anytime, thank you Paul.

Paul: Okay, great. So I wanna remind everybody that we have the Everything Building Envelope Newsletter, and if you’d like to receive that all you need to do is text the world BuildingEnvelope, it’s all one word, BuildingEnvelope to 22828. So if you’d like to receive the Everything Building Envelope Newsletter, just text the word BuildingEnvelope to 22828. I’d like to thank everybody for listening, and until next time, this is Paul Beers, saying so long.

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