DEEP DAMP CONCRETE - The Challenge of Concrete Moisture Issues

CHRISTINE: Hello, everyone. Hi, Alex. Welcome to our webinar. For today, we’re going to be diving into Deep Damp Concrete. My name is Christine. I’m based in the Napier office in Hawke’s Bay in New Zealand, and I am responsible for the specification consulting side of things. So mostly working with engineers and architects to advise on how best to specify for concrete. And I’m joined by Alex, who can introduce himself, across the ditch.

ALEX: Hey, everybody. So basically, I’m Alex Portelli. I head up the same sort of systems as Christine looks after in New Zealand. Just based out of Sydney, Australia.

CHRISTINE: Yes, perfect. So if you aren’t familiar with how we run these things, I’ll just do a little bit of housekeeping, I guess. We appreciate and we love interaction. So if you’ve got any questions at all, don’t fear that they’re silly, and we’d love to interact with you at the end of the presentation. But as those questions pop up, if you want to just utilize the Q&A button down in the bottom toolbar of the Zoom meeting, then we’ll answer those at the end. Yes, as I said, just keep firing them in as you think of them and then we’ll get to all of them and we’ll address them at the end. We’ll also give you a little bit of time to add questions later.

First of all, we’re going to kick off with a poll. Just finding out a little bit about why you joined us today and what sort of sector you work in. So if you can answer that, and that’ll help us tailor a little bit more to who’s online and joining us today. I’ll give you about 20 more seconds, I can’t see a counter. Perfect, I see the results. Okay, so mostly building and construction professionals, architects and designers as well. Perfect. Yes, we will make sure that we’re addressing it towards you guys.

So we’ll crack into it. Basically, what we’re going to learn about today is around concrete moisture; what the problem is, if you’re not familiar. I’m sure most of you are, having dealt with that onsite, and as somebody approaches you who’s on site, to put something in place. We’re going to talk about what the problem is, what causes it, and what we can do to mitigate that. So I will let Alex kick off with talking about what the problem actually is.

ALEX: Awesome. Thanks very much, Christine. So basically, we’ve got a bit of Did You Know here, which I’m sure most of you do. But concrete dries at 25 millimetres per month, as the diagram shows. If you’ve got a 150-millimetre-thick slab, you’d be waiting up to six months for this to completely dry.

So with keeping that in mind, obviously, there are negative impacts associated with that. So now more than ever, projects are needing to be completed in shorter timeframes. Due to these tight deadlines, the concrete is not always completely dry when it comes time to actually lay the flooring. Now, another offset to that is that if you’ve got an exposed slab, and it’s wet during the construction process, that timeline actually resets.

So you’re always behind the clock, so to speak. That’s why it’s important to treat concrete early in the project and take advantage of AQURON’s guaranteed moisture-controlling properties that are also backed by a performance-based warranty.

Failure of direct-stick flooring. Basically, based on the incomplete drying cycles of the concrete slab to receive the flooring, it means the moisture is going to migrate up to the surface up after the floors have been laid. Now, this moisture or damp-rising will have a negative effect on any of the adhesives that have been used to actually stick that flooring down and will cause the floors to bubble and delaminate, as you can see in that diagram there.

CHRISTINE: So I’ll take this side of things in terms of, I’ll come in and save the day! What we can do to help you guys is we can immobilize the moisture. So what we do – and you can see this guy working onsite at the time of pour – within 24 hours, spray-applying our hydrogel treatment, and that penetrates up to 150 mils into the slab. Even though it’s spray-applied on the surface, it’s chemically attracted into the slab, and that transforms all of that residual moisture in the slab into a hydrogel state permanently.

A hydrogel is similar to what you’ll find in your baby’s disposable nappies. So it transforms the moisture into that gel and doesn’t allow leaks. So it’s working on a similar basis. We can save you time and money on that side of things by just treating it at the time of pour.

So you might be wondering, what hydrogel is made of in terms of is it harmful, and where are we getting this from? Concrete hydrogels, the ones that we utilize, are no-VOC and non-toxic. They’re safe for humans to handle. They’re safe for application in any environment, even sensitive marine ones. But what we’re doing is we’re treating the concrete with a catalytic silica. That creates and induces the formation of more of those Calcium Silicate Hydrate (CSH) bonds inside the concrete, which is essentially the building blocks of concrete itself.

So we’re creating more concrete inside the concrete, and we’re not introducing anything into the concrete that doesn’t already chemically exist. As I said, it’s locking 150mm in; it’s locking all of that moisture in place in a hydrogel state permanently, which then starts feeding more bonds inside the concrete.

If we go to the next slide, this is a little illustration of what’s happening in the zoomed-in view. So essentially, when the concrete is poured, it’s left with all of these tiny highways and byways for moisture to move about in and transport impurities, or migrate out and damage your floor coverings.

This is on a nano scale. So we’re talking about…not 50 millimetres, 50 nanometres! – for your typical concrete pour. To give you an idea, a human hair is about 100,000 nanometres, and our technology is working on a scale of about 10 nanometres. So it’s able to penetrate right in, including that attractant that draws it into the slab, and all of that moisture is being transformed permanently into a hydrogel state. If we can stop that moisture moving out of the slab, then we can take care of your curing as well if it’s treated at time of pour. Two, we can guarantee that moisture is not going to go anywhere and damage your flooring.

We’ll go on to the next slide. Yes, so I’ll let Alex talk about a little bit of our new news in terms of this. We’ve always been pretty safe. But Alex, I’ll let you chat about this one.

ALEX: Yes. Thanks, Christine. So as Christine mentioned, our products are nil-VOC and have always been completely environment-friendly and safe to use in all applications. However, what we’ve done now is we’ve recently had the Environmental Choice tick of approval, which is now recognized by both the Green Building Councils of Australia and New Zealand.

The two best products to talk about when talking about direct-stick flooring, etc, are the AQURON 2000 and AQURON 2000 MEDI+. As I mentioned, both of these products will work towards a Green Star rating if applicable on the project.

CHRISTINE: Yes, absolutely. We have a few more in our stable that have been awarded the tick, but for the purpose of moisture control, these are the two. Cool!

ALEX: Next slide, please. So we’ve just got a couple of case studies here today. The first one here is the Caversham School in WA, which actually took full advantage of AQURON 2000’s curing and moisture-controlling characteristics, by utilizing it at the time of concrete pour. By doing this, they saved significant time and money across the project. Now, this is the ideal type of treatment to use when a moisture barrier or a moisture-controlling agent is called for in the specifications or bill of quantities in a project.

CHRISTINE: I think the next one is an NZ one, so I’ll take that one. Yes, Nelson Airport. So this one here, obviously being a busy airport, it’s under strict time constraints to get back up and running to stop sending its clients around different barriers. So late on in the project, they poured a topping slab and that was going to throw the whole schedule out, because it needed time to dry and to be safe enough to lay floor coverings.

So AQURON 2000 was applied at the time of pour. As I mentioned earlier, that took care of the curing. It’s an equivalent to 14 days water cure, which exceeds the typical seven-day water ponding required. Then it also meant that they could lay floor coverings after 28 days, and full flooring replacement warranty means that we’re not just going to throw more product at it. If there’s moisture damage due to the moisture coming out of the slab, we will pay for the full replacement of the flooring. So people can have peace of mind about that.

As you see at the bottom of the slide, this won an architectural award. While we can’t claim that that had anything to do with us, we do like to celebrate when projects we’ve been involved in have won an award! I think there’s another Aussie one which was applied later in the game, rather than at time of pour.

ALEX: Yes, that’s exactly right. So basically, this project here, the Coles Richmond (Dimmeys Building). Basically, the scope of works was to keep the external facade original and intact, however, a brand-new Coles was to be fitted out within the internal space of the building. So we were actually commissioned by the flooring contractor on this project, to apply the AQURON 2000 for moisture control, post-curing, but prior to the flooring actually being installed.

Although we completed this at the back-end of the project, we were still able to honour our moisture-controlling performance-based warranty; to ensure that even though there was a high reading of moisture, that there would be no effect to the adhesion of flooring glues for that project. So pretty good and interesting one, just goes to show the versatility of our products, being able to be used either at the beginning or the end of a project.

I’ll take this one as well. So we’ve had some recent insights to the changing standards, particularly the Australian Standard 1884, which relates directly to resilient sheet and tile floor coverings. With a more stringent standard for the emphasis on moisture controlling that the traditional systems no longer comply with, what MARKHAM have done is we’ve got together with our tech team. We’re actually going to be releasing a new system called FLOOR-TECT™, which is going to meet the requirements of the new standard to 100%. That will be released early 2022, so watch this space for that exciting news.

CHRISTINE: Yes, that’s short and sweet for our presentation today. That’s kind of the end of the formal part. But we would love to answer any questions and back and forth with you now. If you’ve got anything at all about specifics, about where you can utilize it and what the stand-down time is for existing flooring being treated, I’ll give you a couple of minutes for that.

Yes, one question. If the floor coverings are replaced, does the treatment needs to be redone? Great question, I will answer that. So essentially no, because the treatment is within the slab itself. It can’t be abraded or removed. This is a great aspect in aged care scenarios; we’re utilized a lot. That means that in between residents, if the floor coverings are replaced, as often happens in a retirement village, there’s no surface moisture barrier that needs to be redone, because the slab itself has the moisture barrier. Alex, do you want to take the warranty question? [How long is the warranty?]

ALEX: Yes, no problems at all. Basically, with the warranty, a standard warranty starts at 15 years for moisture control. If their design requirements are project specific, that needs to be extended or negotiated upon – if we’ve got a certain level of design input within that scope of works as to when we can apply it etc. – we can always look at extending that warranty if it is required.

CHRISTINE: I’ll take the approximate cost for NZ. [What are the approx costs per m² for a new concrete floor?] I mean, every project is slightly different. But in NZ your typical cost, so that includes curing and moisture control, that comes in at around $9–10 per square metre, or up to $11, depending on whether it’s also a MEDI sealer as well.

ALEX: Absolutely. That also has a factor based on whether it’s at the time of pour, or whether we’ve been got to apply it retrospectively and work in with other trades, etc. We look at it as, I guess, holistically, and we try and get the best rate for the project based on the restraints or the constraints.

CHRISTINE: Perfect. Robert, you’ve asked: Is the moisture barrier tacky at all? No, we leave the top few millimetres unchanged. This is part of the reason why we can guarantee compatibility. Because the treatment is penetrating, so it’s within the slab and it’s not introducing anything that doesn’t already exist in concrete. So that’s one part. But it also leaves the top surface unchanged. It doesn’t need to be ground-off ahead of floor coverings being laid, and you shouldn’t be able to see or touch any difference at all once that’s been treated. I think that one is done.

ALEX: I’ll grab the next one. [Can AQURON 2000 be used under a waterproof membrane for an external concrete slab with tiles over?] Pretty much Christine touched on this just in the previous comment. Being that we’re penetrating in 150mm and leaving that top surface exposed, we are essentially compatible with anything that is compatible with natural concrete or untreated concrete. We’re not putting anything into the concrete that shouldn’t be there or that is foreign. So to answer that question, yes, it is compatible. It can be utilized with membranes. We have done that in the past as belts and braces systems for certain projects. Yes, basically, compatibility is not an issue at all.

CHRISTINE: Yes, and it’s covered by our warranty. We’ll guarantee compatibility with any following adhesives, floor coverings, line-marking for car parks. But that’s not what we’re talking about today. So yes, perfect.

I’ll take the next one from Robert. Do slabs that have heavy traffic between application and laying of floors need any further treatments? So that’s an easy one as well. Same principle, because it’s internal. We also utilize a form of this for our durability treatments as well in car parking buildings. So there’s nothing to protect, and it’s all internal in the slab. It’s creating more concrete in the concrete, and it’s making that slab impermeable to moisture, but it’s also increasing the density and durability. So there’s nothing on the surface that can be worn or abraded off. 150 mils into this slab means that it’s not in any danger of being abraded off by any traffic or following trades in between.

ALEX: That’s bang on! Just have a little bit to add to that point. It also works extremely well as an anti-duster during the construction process. Quite important to mention, based on the fact that we are increasing the trafficability by about 70%, or the abrasion resistance.

One factor to note, which actually ties in probably to the next question, which I’ll answer all in one. It’s the fact that although nothing else has to be applied to the surface prior to flooring going down, we do highly recommend that the “8 Rules and 5 Precautions” outlined by MARKHAM are followed. That’s basically just to make sure that the flooring contractors still follow their general principles in regards to laying flooring.

To ensure that there is a key in the slab so that the glue will adhere to something, and that the floors aren’t over-trowelled during the finishing process by the concreter. That’s something that we try and step in and negotiate on behalf of ourselves, and also the flooring contractor as well, so that everybody’s happy when it comes time to lay floors and no one can point blame if the floor is too smooth, basically.

Regarding the difference of the products [What is the difference between the 2 products?], essentially the base of the product is both the same, hence the 2000. The difference between the 2000 and the 2000 MEDI is a unique acrylic in the 2000 MEDI product, which actually rises to the surface, still remaining underneath the surface in order to lay flooring and glues. But what that acrylic does is actually stopping any bio fluids to be able to actually penetrate into the concrete matrix – to eliminate smells, odours, etc – if there were to be that sort of form of spill on the floor.

CHRISTINE: It stops the bacterial activity happening in slabs as well.

ALEX: Yes, it gives the bacteria nothing to be able to cling on to in hindsight.

CHRISTINE: Yes, nothing to work with! That seems to be all the questions for now. You will get a follow-up email after the end of this webinar, with our email addresses on that were on the last slide there. So, if you’ve got any further questions, obviously Aussie queries go to Alex and NZ ones to me, and we’d be happy to help you out. Happy to help at any level of your project. Yes, thank you for joining us.

ALEX: Absolutely. Well said, Christine. Look forward to it. Thanks, guys.