What’s the problem with concrete under floor coverings?

BRENDAN: Well, g’day all, and welcome to the latest podcast in MARKHAM’s Invisible Strength series. We’re here to ask, What’s the problem with concrete under floor coverings?

I’m Brendan Stead of the marketing team, and with me today is Henry Mitchell, Sales Team Leader in our head office in Napier, New Zealand. Henry, give our audience a shout out, and tell us about yourself!

HENRY: Yes, thanks Brendan – Kia Ora, everyone! As Brendan said, I’m based in New Zealand with the project and delivery team. I’ve been with MARKHAM for about nine and a half years now. I did about 18 months in the Aussie team, and have come back to the sunny Hawke’s Bay.

But yeah, hopefully, I can share some learnings with you guys today and tell you a little bit more about where we can help you.

BRENDAN: Thanks Henry – great to hear you! And from our Sydney team, we’re hearing from Wade Lanham, currently our NSW project consultant. Wade joins us from his home office due to the restrictions currently in the area at the time of recording. Wade, give us a run-through!

WADE: G’day! Yes, I’m Wade, I’ve been with MARKHAM for about three years now. Currently working out of the nice, peaceful, quiet Home Office rather than the noisy Sydney office at the moment.

I’ve been helping architects, builders and almost everyone in between that, come up with solutions for their builds. I tend to focus mainly on the topic we’re talking about today, which is moisture control under flooring. So yeah, quite a lot of experience in that area. So yeah, be good to go through it today.

BRENDAN: That’s brilliant, thanks, Wade! So as I mentioned, we’re chatting today about concrete under floor coverings. Henry, can you give us some context, what is this topic really about?

HENRY: Yes, thanks, Brendan. So it’s going to be about floor coverings that are glued directly to concrete slabs. And it can include carpet, vinyl, tiles, sports flooring, rubber. So a wide range of flooring there.

BRENDAN: Is the direct stick method a problem?

HENRY: No, it’s not a problem; and I guess what you’ve got to understand is that concrete must be internally dry. Otherwise, you get moisture rising up. The humidity in the air often “pulls” the moisture up out of the concrete as such. And then we get things like delam, dissolving of the adhesives, causing vapour bubbles; particularly bad in vinyl areas, that sort of thing, but not uncommon for carpet or other types of coatings as well.

So what you’ve got to understand – concrete dries at a rate of 25mm per month, and that’s … you get a 150mm thick slab, that’s about six months in your build program that you have to wait for the concrete to get down to 75% relative humidity before it’s safe to lay floor coverings. So that’s a long time in any build program. And you’ve got to understand, that’s not from the time of concrete pour, that’s from the last time the concrete was wet, as such.

BRENDAN: OK – so, Wade, can you give us your take on this, you’ve seen these sort of issues – how do you meet them?

WADE: Yeah, really good question. It obviously is a big issue. People always think that we need to get the concrete as dry as possible, it’s dryness in the concrete that we need. And it’s true, we can’t have moisture under these floor coverings. But what we’ve got to try and do is actually bind up the moisture so it can’t escape from the concrete. That’s the biggest thing that we try and do it. It’s not so much us drying out the concrete, but it’s locking up that moisture so the moisture can’t cause problems to things like the flooring.

BRENDAN: Right, so how do we actually do that?

WADE: Yes, good question. So our approach is not actually to dry out the concrete. It’s not to push the moisture out of the concrete, but we actually lock up the moisture inside the concrete so it can’t travel. The way we do this is with a colloidal silica hydrogel treatment. Now what that is, it’s tiny atomised silica. It’s suspended in fluid; it’s sprayed onto the concrete, and the particles size is so small that it can penetrate deep inside the concrete. And it actually changes the form of the moisture in the concrete. So where it would normally be your water, type thing, we actually change it into a gel. So that gel can’t be moved around the concrete and actually, over time it will actually form more calcium silicate hydrate, which is the bonding agent in cement.

So I guess we’re filling what would normally be voids and moisture with more of the good stuff to concrete.

HENRY: Yes, that’s good Wade. And I guess, just understanding … for the people that are listening online – understand that we’re transforming that moisture so it’s no longer moisture in concrete.

And there are other benefits too. So with the hydrogel, it actually feeds the hydration process in concrete, so we get the benefit in curing at the time of poor. It can replace multiple products and processes. You don’t have to put a curing membrane that’s not compatible floor coverings that you might want to come back and grind off later. So yeah, saving time and money is what we’re about as well.

WADE: Yes, you’re spot on there, Henry. It’s really, really useful in things like medium to large retail outlets where you’ve got to think, there’s lots of vinyl flooring. You’ve got things like grocery stores like Coles, Woolworths, so you guys call it Countdown in New Zealand, all those types of things … and then even retail centres in shopping centres, and things like that, where there’s lots of that vinyl flooring. It really does help them out.

BRENDAN: OK, so is there a flip side? Do you have instances where it hasn’t worked for us?

WADE: There were a couple of instances where it was thought to have failed. One turned out to have the sun beating on the newly laid floor coverings through an unusual window, so it was actually a heat issue that caused an issue there. We thought it might have been our first fail, but it turned out there was a bit of a unique situation.

There’s been another case where there’s actually water oozing through the walls and down under the floor. So we have seen failures, but the more we looked into failures, the more we realise that it’s not the issue at all of us not being able to lock up the moisture in the floor. It’s controlling moisture from other areas as well, which is really important. We’ve been doing this for quite a long time. So around 25 years we’ve been doing this now. We treat around 100,000 square metres a month, and we’ve got a really strong performance-based warranty as well, which is not just the replacement of the product, but also the reinstatement of the flooring if it is a concrete moisture issue in that as well. So we’re really experienced with it, and we really do stick by our systems as well.

BRENDAN: That’s excellent! So – what does the treatment compare to? What other products are in this space?

HENRY: Yes, I guess there are other moisture controls out there, but there’s very few that we know that have got the deep penetrating capabilities of the hydrogel, that can penetrate up to 150mm into your concrete. You’ve got paint on coatings before floor coverings. You could go down the track of hydrepoxies, but they’re up around the $30 a square metre mark. Usually more expensive than what we’re offering, but they don’t give the curing benefits as well. So yes, there are other systems out there.

But I guess MARKHAM has got a bit of a different model as well. We have our in-house applicators or installers, our in-house QA team and operators, PM’s do all that work. And we can tie that all together for our performance-based warranties. And then obviously passing those insurance back warranties on. So yes, as Wade said, if there is an issue we would cover replacement of floor coverings, workmanship, the whole lot, and that’s just because we hold all that QA and install together quite tight from day one.

BRENDAN: Excellent, excellent! And any other points, any other benefits we haven’t really touched on? Anything we need to …

HENRY: Yes I guess we can just reinforce that idea of curing of concrete. So the hydrogel gets into the concrete, green concrete, forms a hydrogel, feeds the hydration process. It’s been tested to be equal to 14 days water ponding. So good curing of concrete! A lot of people don’t think … a lot of architects out there probably think that curing is in the engineers’ basket; but you get good curing concrete, you get more durable concrete from day one, and obviously longer lasting. And then you get your moisture control. Yes, your whole system is done in one shot.

BRENDAN: Very good. That would have to be serious savings in time and money.

Well, thank you very much for your time today, Wade and Henry! It’s been great going over these details. And to our listeners – why don’t you visit www.MARKHAMglobal.com and check out our key concrete treatments, or get in touch with us! Stay safe, all, and don’t miss our next episode.