Waterproofing Structures, Products, Feedback and Scenarios

(Released on June 15)
  Check out GCI’s Article on waterproofing. 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


Check out GCI’s Article on waterproofing.

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, really excited about our guest today, David Gehlbach with CETCO. He’s technical sales manager in Florida and the Caribbean, and really has his finger on the pulse in the waterproofing business. Welcome, Dave.

David: Nice to be here, Paul. Appreciate the invite.

Paul: So before we get into talking about waterproofing, maybe you could just share a little bit of your background experience with the audience?

David: Sure, sure. I’ve got a fairly diverse background in construction industry, roughly 25 years total in the architectural and waterproofing/roofing industry. I started out…graduated from college with a degree in architecture and became a licensed architect in 1996, and then kind of transitioned into becoming a manufacturer sales rep from there. I’ve worked with deck coatings, urethane and silicone sealants, anything that’s related to a building envelope and moisture intrusion, I’ve kind of been involved with.

I worked for a major waterproofing company from 2002 to 2008, and then, from 2008 to 2012, I kind of bounced around as an independent consultant, dabbled in some concrete admixtures and moisture issues related to flooring, and then I started with CETCO in 2012, so I’ve been there for a little over four years now.

Paul: Great, and for those who aren’t familiar, I’m sure many are, could you tell a little about CETCO, who they are, and what they do?

David: Sure, CETCO is a global international company, and I am underneath the construction technologies division that is owned by a mineral tech incorporated. And the construction technologies consist of environmental sciences drilling, and a tunnel division, and then where I sit is the building products division, and that is focusing on sub-grade waterproofing with the use of active bentonite and polymer type systems.

Paul: Let’s talk a little bit about, what is bentonite?

David: Bentonite is a natural clay, it is mined out of the earth and it is processed. And I guess the best or simplest analogy would be, it’s kind of like a kitty litter. When moisture comes in contact with bentonite, it swells and hydrates and expands, and that’s basically the simplistic technology behind it.

Paul: So when you use it in a below-grade application, it’s basically put in place, and then as it gets wet it expands and sort of like it you know, seals and fills voids and whatnot?

David: Exactly, and a bentonite sheet, for example, goes on the wall, either prior to pouring the concrete, which will be blindside construction, or it gets applied to the wall after the concrete is poured, and then it always has to be under compaction, either earth or for a horizontal conditions another topping slab. So it’s always under compaction and most used in the sub-grade market.

Paul: I know with our business, GCI consultants, we see I think being used more and more where they’re trying to maximize the use of property and obviously, basements and garages and things like that probably don’t make them a lot of money, you know the dwelling spaces, so if they can put them at or below grade. I think that seems to really help their…what they’re trying to do. So it seems like there’s a lot of those type of applications these days are using that. Are you seeing that?

David: Yeah, the more you get into an urban area such as downtown Miami or downtown Jacksonville where buildings are right on top of each other, you end up producing that filling, like you said, with a sub-grade garage for parking. And it becomes a property line condition where you’re going to blindside application with either sheet piles or wood lagging or some sort of system similar to that.

Paul: So CETCO has… Their footprint extends throughout the US and beyond, is that right?

David: Correct yeah, there’s a European division as well as North American division, and we also have a South American division that’s starting up strongly as well.

Paul: So I would imagine that your turf, we’ll call it, or you’re territory, is probably one of the bigger challenges given water table is so close to the surface in Florida as compared to some other areas where it’s probably not.

David: Yeah, definitely, that’s definitely true. And that is the case in Florida, we got really practically the whole perimeter of Florida except for the Panhandle is waterfront and the state as a whole is relatively flat except for a couple areas here and there, but most of Florida, you’re right, within three feet or thereabouts.

Paul: So what’s your philosophy with waterproofing the structure?

David: Well, I think, first thing is to ask a lot of questions and understand what the individual needs are of the project and that comes from obviously, are we in the water table? Do we have a hydrostatic condition? Also what the owner is looking for, are they looking to hold onto the building after they’ve built it for 10 or 15 years or more, or are they looking to just build it quickly and cheaply and then go ahead and sell it?

Because that will kind of drive the discussion of what type of waterproofing systems they want, how long they want the warranty, what type of warranty they want, whether it’s just the material only or a no dollar limit, everything is included, type warranty. And then there’s the physical considerations, you know, where are we with the flood areas? Where are we next to other structures? Geographical areas, water test. All those type of things start to come into play as well.

Paul: Does the same product or system fit all applications?

David: I mean, that’s a double question. There’s a yes to that and there’s a no to that. As an overall answer, our products, the bentonites and the polymers, would address all the different conditions. Inside of our product lines we have different levels, we have a salt water bentonite, which is the Voltex CR, that would address a site that has a little bit higher of the salt or a contamination in the soil. And then when we go even beyond that, what we have very high salt and contamination, we have a polymer product called Ultraseal that we jump to that can address Miami Collins Avenue right on the Atlantic Ocean where we have salt contents that are fairly high. So we have different levels and different types of bentonite and polymer products to address all the situations.

Paul: What’s done differently with the Ultraseal and the high salt environments opposed to just the standard product that you may get in Atlanta or St Louis or somewhere like that?.

David: Sure, yeah, the standard bentonite on our product is 1.1 pounds per square foot, there’s other manufacturers that also have an entry level bentonite that basically addresses all your, you know, normal average salt contents and contamination contents for each site The trick is, when you get to a high salt content that bentonite can stop swelling as much as it should, it doesn’t hydrate as much as we’d like to see, so manufacturers went to a saltwater bentonite.

So a lot of products you know, you jump off to that saltwater grade. What we found, when we started getting exposed to the European market, like United Arab Emirates for example, some of those areas have a salt content in the 4% range as opposed to Miami, which is a very high salt range in the 3% range. So we went ahead about 10 years ago, somewhere around 2007 and we introduced the Ultraseal, which is a polymer based product.

So the entry level bentonites are strictly 100% bentonite at 1.1 pounds per square foot in the product. When you jump to the Ultraseal, just manufactured by CETCO, that has roughly 85% polymer, with about 15% bentonite. And the difference is the polymer hydrates and swells even in the very highest of salt contents.

Paul: Interesting, so when an owner or an architect is getting into a project, of course, you’re in there talking to them early, as the… You’re probably one of the first scope items that go in, how should they be doing their research consider the possibilities and make good decision? Is it a good idea to get several different sources of feedback when starting a project?

David: Sure, that definitely by all means. You know, one of the things that we recommend in our part of the industry is to get someone like you guys, get a waterproofing consultant involved early, who’s been down that road before and understands what should be used, and I guess, for lack of a better phrase, what shouldn’t be taken out of a project. So yeah, get advice from waterproofing consultants, bring in the manufacturer’s rep like myself and then also maybe call two or three top waterproofing contractors.

I know that when high-rises get built with glass and dow silicone, I know sometimes even two years before a project’s started they bring in a large glass contractor to kind of get an idea of what the budgeting is gonna be. And I think that’s something that GCs and owners should take advantage of. Here’s the contractors that are actually doing the work, get some feedback from them.

So I think it’s important as yes, get as many people involved upfront as possible and gather as much information as you can before you start [inaudible 00:11:09] a project.

Paul: You know, we’re big advocates of involving manufacturers, of course, but also the contractors, the guys who have to build it, and who are in the marketplace every day, and as you say, if you get all the different perspectives that everybody gets together and you know, basically can work out the best solution for a particular scenario or project.

David: Yeah, and that process also avoids some uncomfortable situations that I’ve personally been involved in where a contract is being awarded to a waterproofing group and the owner is under the impression that it’s roughly three to four times as much money as he thought it was gonna be. And the question goes back to the owner of well, you know, where did that original number come from, 16 or 18 months ago?

And there have been times where owners have said, “Well, I don’t know. We made a couple of calls and we plugged, you know, \$3 a square foot for the waterproofing.” Meanwhile, the specification has a couple of systems listed that may be in you know, \$12 per square foot range.

Paul: That’s one of my you know, pet peeves as where maybe it is that these budgets get set early during pre-construction, waterproofing and other things and then you know, comes project time and budget is inadequate and the money is not there and it really causes a lot of angst and the stress of trying to figure out you know, what we do? Do we just not do it the right way? Or how do we you know, steal money from somewhere else? And as you say it’s uncomfortable and not always resulting in a good decision.

David: Right, exactly. And we talk about the, you know, the percentage of waterproofing as a total of the project cost. For example, a condominium that someone is building near the beach, units may be going for three to four million or even more per unit, the total building cost is maybe \$120 million, and here we are sitting with the owner and they’re trying to get rid of, you know, \$300,000 worth of waterproofing, which you know is a very important entity to a building but with all the lawsuits and the liability that the architect takes on.

The 558 lawsuits, that I think most people who are listening to this understand what those are about, and it’s just important to point that out to say you know, “You’re taking out less than 1% of the total project cost for something that most times ends up being 96% to 98% at the time of the lawsuit based on moisture mitigation, mold, health hazards, issues related to that.” So I think it’s important to point that out. And you can’t do waterproofing after the fact like you can some other scopes of work. It’s a one-shot deal, you either do it or you don’t.

Paul: So have you seen scenarios where owners have…shouldn’t keep blaming the owners, where projects have omitted waterproofing materials, maybe not made good decisions? What happens then?

David: Yeah, you know, worst case scenario was… And I’ll keep the names out of it but you know, worst case scenario is the owner doesn’t have a budget for the waterproofing, and I think it was in that \$350,000, \$400,000 range, value engineer had all the waterproofing. Fast forward a couple of months we’re in the middle of the project and they just couldn’t control the water that was coming through the concrete that was poured, they ended up having to pour a four-foot tremie slab, and do the waterproofing anyway, but what that did was they lost the floor of parking which threw off their units to parking ratio.

They lost a couple units, and I think the total cost to that project was roughly 11 to 12 million after it was all said and done. Granted the total project was probably 120 million, so it was 10% of the project. But once again we go back to, how much was the waterproofing scope if they would have just left it in and did back and got a decent warranty? You know, much less than 12 million. So there have been instances where decisions get made and then 8 months to 10 months later, we get phone calls.

Either the manufacturer gets a phone call or the architect or the consultant such as yourself, get a phone call, “Hey, we need you guys out here, we’ve got leaks all over this basement.” And then the forensics start, “Well, was it waterproofed? Was it inspected? And what type of system was used?” And you go down that whole road of trying to figure out what happened. It can lead to saving a couple of dollars and then ending up spending many more dollars injecting or trying to fix those water’s intrusion points.

Paul: Penny wise and pound foolish once you get into the, “What happened phase,” it’s probably too late.

David: Right, exactly. And without trying to be perceived as a pushy salesperson, I try to educate the owners and the general contractors on the decisions that they’re making. You know, “There have been other people that made these decisions, here’s what happened. I’m not saying that’s gonna happen to you, but these are scenarios, worst case scenarios that have happened.”

So it is a little bit of a gamble when they decide to just not do anything or waterproof half of it or roll the dice because the water table is a little bit lower. Over on this half of the project versus you know, over on that half of the project, the concrete is a little lower, so we should waterproof that but not the other half.

Paul: You know, I’ve seen projects where they tried to piecemeal it, and I was gonna say, playing fire, but they’re playing with water. But it’s scary because if you blow it and as you said, as you were describing with another project, it can be pretty catastrophic.

David: Yes, can be.

Paul: So when you do get asked a question about cost by owners, architects, GC’s, how do you handle that?

David: I mean, that’s a touchy situation because costs can vary immensely depending on how many mobilizations there are to a site, access to the site, how long a job is gonna go on. So there’s a lot of variables that affect that, but I think the range of pricing and the way we used to do it with scheduled values, you’re plugging in an estimate into each one of the scopes of the work. So for example, if you’re owner and your project team is looking at a five-year warranty on the entry-level bentonite product you know, those are usually \$7 a square foot plus or minus, could be lower could be higher.

The market affects that as well. If waterproofing contracts are aggressively looking to get more work, the price is obviously gonna be lower you know, as it was in 2009, and in those times when there was not that much work around. On the flip side, if it’s a very busy as it is now, the bids tend to gravitate a little bit higher. But you know, a number within 10% or 12% to 15% of what it should be, should be an easy thing for an owner and an architectural firm and a project team to have in that box.

So you know, five-year systems, like I said, anywhere \$7 plus or minus a square foot installed, and then when you get into the 10-year systems, that’s plus or minus, you know, \$11, \$12 a square foot in that range. And once again, those could be slightly higher or lower, but that’s kind of exactly how I answer that question to an owner. You know, “Here’s your range.” What we do wanna avoid is what we discussed before is, let’s say you have a desiccation and a project team that is heading towards a special warranty in the 10-year time and they have products that are in that \$12 range, you don’t want the general contractor to just pull a number out of thin air and say, ‘Well, let’s just plug \$4 in there.”

You know, that creates those uncomfortable scenarios 18 months later where they don’t have a budget for the job, but it’s because they didn’t do the due diligence before hand and find out how much stuff should cost. You know, and that’s the same for other products that I don’t sell, deck coatings, perimeter sealants around the windows, roofing. You know, they all have their price categories and ranges, and that should be something that a project team should get a handle on early in the process.

Paul: You’re just mentioning warranties, I know CETCO has different warranties available with different products and different programs and whatnot, can you talk a little bit about that?

David: Yeah, sure, warranties are important. A lot of times the project team will focus on the year, you know is it a 5-five year? Is it a 10-ten year? Roofing and plaza decks are most commonly 20-year warranties. And although the year is important, it’s also important to ask the next question, “Okay, what type of warranty is it? What’s included in the warranty? Let’s run through some scenarios on what happens if we have leaks.”

The warranties are kept in a way where you know, a good/better/best scenario where most initial warranties are material only, and that basically states to the owner or the project team that you can prove that the material is defective in and of itself, the manufacturer will participate in that warranty. The challenge with sub-grade work is that now you have 16 or 20 feet of dirt or earth, hardscape above that in urban areas you have tight property line conditions where to dig down 20 feet to fix something is really not cost effective and is not something that you can easily do.

So a lot of times with sub-grade waterproofing, you end up addressing the leaks from the negative side which is the interior of the building. So that warranty you know, it is what it is. I guess I’ll just say that.
The next step is a material and labor warranty where the manufacturer will participate in covering the material and the labor cost. However, most commonly there’s a sentence somewhere that says, “Warranty is limited to the original purchase price of the material.” So obviously, the price of the material at X dollars a square foot doesn’t include the labor to install it or the labor to remove it if you need to replace it, because that can be you know, something that’s \$3 a square foot to buy can be \$10 or \$12 a square foot to install.

So those warranties, although they are warranties, what CETCO did about 10 years ago is kind of asked the question to ourselves, “What type of warranty could we offer if it was a no dollar limit, no questions asked, we’ll fix the building until it’s dry type warranty?” And we came up with what’s called a hydrashield quality assurance program, and in a nutshell, what that does is it basically gives a warranty to the owner and the project team that if there are any leaks in the building we fix them, no questions asked, with injection technology from the interior of the building.

And there’s a couple of things that our team put together that have to happen to get that warranty, to be eligible for that warranty. And that is hiring a certified inspector and a waterproofing consultant such as GCI, there’s a total of about seven or eight of them throughout the state that we have a list of. And then the second item is that we have to have an approved applicator who’s part of our hydrashield warranty program. And there’s about, I would say 15 to 18 contractors throughout Florida and the Caribbean that are approved applicators to do that work.

There’s a mandatory pre-con meaning that takes place prior to the start of construction and then the waterproofing consultant inspects that installation and the backfill throughout the process of the sub-grade installation. And then there’s constant communication with CETCO’s field service unit, and it’s basically a system that’s put in place to inspect all the waterproofing, make sure that it’s installed correctly prior to the backfill. So then when they’re finally done with the project, you get that no dollar limit warranty.

Paul: When CETCO [inaudible 00:23:48] no dollar limit warranty, they have good confidence going into it because of the process with having everybody involved having the independent inspections, having the technical team that it’s gonna have a good outcome and it’s gonna be a win for everybody.

David: Yeah, most likely, not just with CETCO as a manufacturer, but most manufacturers products that are tested, they work if they’re installed correctly, but it’s the penetration that was missed on a wall, it’s an electrician or a plumber drilling a six-inch diameter hole through the wall and not telling anybody. It’s those issues and the lack of communication with the project team, that’s where those leaks… In my opinion 99% of the time, leaks to a building come from those type of scenarios, not from just the product failing.

It’s usually a penetration, a missed detail, a termination bar was not done correctly, something along those lines. So with that owner hiring the independent inspector and working closely with the waterproofing contractor and CETCO field services with constant communication you know, we try to catch all those items before we backfill and before we finish a project up.

Paul: If you do have the rogue penetration, I’ll call it, that for some reason slips through the cracks for whatever reason, can that be fixed after the fact?

David: Yeah, I mean if we can get to it from the outside, that’s fine. If we need to inject it or address it from the inside we can do that as well.

Paul: So, Dave, let me ask you, what’s a day in the life of a manufacturer’s representative in your waterproofing space? What do you do on a typical, or I guess even atypical day?

David: Sure, yeah, we do a lot of different things. We have interactions with architects, general contractors, waterproofing contractors, owners, consultants. In a typical day, you may get a mixture of all those in one meeting or you may have individual meetings you know, with an architect to discuss that upcoming project. Maybe some needs that they have for you to review, their specifications or they just wanna talk about you know, something they have going in a specific project that’s already being done that they just wanna bounce an idea off of.

So we wear many different hats, you know, we can be down in a 30-foot hole looking at a sub-grade waterproofing condition and then be you know, in an owner’s office for lunch, and then be doing a presentation at a CSI event later that evening. It’s a constant juggling of what we do. The goal of what I do personally is to become a resource to the architects and the owners in the GCs and the waterproofing contractors that use our products. As I said in the beginning, I’ve been doing this for roughly 20 years or so, and I know it’s important for someone who calls up and just wants something answered, even if I don’t know that question, I pride myself in the fact that I have a lot of contacts throughout the industry and I’ll end up getting the answer for that person.

Now a manufacturer’s representative, in my opinion, shouldn’t just be pigeonholed to his one product group because construction has so many different transitions from one scope to the next, you know, for example, what happens at the top of a wall when the waterproofing ends? Do you transition into EIFS system, stucco system, a brick system, are there through wall flashings? That transition point is very important to the architect because they’re looking at the whole project. So I think it’s important to not only understand your specific product and how that is installed and how that goes in a project, but how some of the other items in the scope of your work, what touches your product? How do those transitions work? Because that’s, you know, that’s important to me.

Paul: That’s what I said when we started, you really got your fingers on the pulse I think and going on in your territory at Florida and the Caribbean and I can personally attest that a really great resource for people who need to get some good quality advice with regards to the various water proofing elements.

David: I appreciate that.

Paul: So if somebody wants to learn more about CETCO or get a hold of you, how would they go about doing that?

David: I’ve got a number of ways, everybody is welcome to call them on my cellphone, and I’ll give that number that’s 407-450-2429. Also our website is And then I’ve also got and email, it’s And my last name is G-E-H-L-B-A-C-H, and the minerals tech is basically how it sounds, and T-E-C-H at the end.

Paul: Great, so I know that it was a really good topic that we had today and I really appreciate all the wisdom that you imparted with us. I know this is a big concern and hot button with our customers that really come from something that was… I would say…was going to say obscure, but something that really wasn’t in the forefront and now it’s really out there and it’s becoming a bigger and bigger part of these projects, so I know that’s gonna be a lot of interest. And thank you very much for coming around today.

David: It was a pleasure, as I said I appreciate the invite, and happy to join you.

Paul: Great, so I’d like to remind everybody that we have Everything Building Envelope newsletter and if you would like to get on the list and receive that all you need to do is text the word buildingenvelope, all one word, buildingenvelope to 22828. Again, text the word buildingenvelope to 22828. Thank you, everyone, for listening, it was a really interesting topic again. And thank you again, Dave.

David: You’re welcome.

Paul: And until next time, this is Paul Beers saying, “So long.”

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