5 Biggest Waterproofing Myths Busted

[Shane Clarke] Morning all. Welcome to our webinar. We're just going to wait about 30 seconds while the people enter the room. Make sure you've topped up your tea. All right. Kia ora tena koutou everybody. Welcome. Welcome to Nuralite’s education webinars. This is our 11th webinar in the series. You're lucky enough to see this one live. For our past webinars, etc, you can jump onto our website and see what we've been up to, what we've covered. We've also got some webinars up and coming as well. The next one we'll be talking about best practise waterproofing solutions below ground. Anyway, for those of you that don't know me, my name's Shane. I'm the general manager at Nuralite Waterproofing Limited. I am more than honoured today to have on the panel with me an internal webinar, which is great. I've got David Kan and Peter Mills with me. These two are our frontline tech reps, if you like. And for those of you who've been on our website, you may notice they pop up on the live chat. So they're actually real live people, not bots. So these guys actually are at the forefront every day of the technical questions that come in and get asked. So that's why I've got them here on the panel today. Also, this webinar, we are sponsoring the charity Riding for the Disabled, which I think is a really great cause. It was established in 1972. They provide, I guess, riding abilities for those who are disabled to help with a physical form of therapy. And it's actually something I've seen in action and I'm all for it. So thanks for participating today. So everybody that's here will be donating $10 per head. So thanks again. You made the world a better place just simply by being here. It's great to see you. I want to start off with a poll to see who's who in the room. It's all about your confidence in specifying a membrane roof. It'd be great to see where we all sit. If you could just feel free to use the keyboards and type in your answers or click the boxes. We want to make this as interactive as possible. Feel free to ask questions in the chat function or the Q&A section. Otherwise, you'll be staring at me talking all morning. It's not as good as you guys can interact. So by all means, feel free to jump in. All right. OK, so. Excellent. There's the sharing the poll results there. Good mix there. Good mix. OK, so what we're going to cover today is five of the biggest myths that we see. And when I say we, I mean people like David and Peter who are at the front line of these FAQs coming through. So they've actually put these together on some of the biggest common misconceptions that we see in the market. So the first myth we're going to talk about this morning is about our PIR insulation board and its fire properties. So over to you, Peter. Oh, sorry, this is David's one. I beg your pardon. [David Kan] Thanks for that, Shane. So PIR as a material can't be classed as a non-combustible. But due to its makeup, it will take a lot to get it going. And this is where other materials will be normally long gone and up in smoke. So let's take a closer look at PIR so we can get a better understanding on how it reacts in different conditions, especially compared to other materials on the market. So if you go to the next slide. Now, we do have a video to show you, but let's take a look at some of its characteristics first. As an exterior component with its closed cell construction, it makes an excellent option to be used throughout the structure, the building structure, and the material also has a fire rating of a 1S fire rating. Now, Enertherm is supplied by one of our sister companies, which is called Outright Continuous Insulation. And also in Europe, it's been extensively tested in many aspects and many factors of the building process. But most importantly, it's suitable to be used right here in New Zealand. Now, as a picture paints a thousand words, a video speaks to it. So let's see what happens to PIR under a flame. Roll camera, please. Now, here we have the laminated torch. These reach about 1400 degrees centigrade. The laminated foil, you can see, starts to burn away quite quickly, but then the PIR will start to burn and char. But you'll notice there's no slumping or melting like some other materials do under these conditions. As it chars, you'll notice that the burning process is actually starting to slow down. And this is due to the materials the PIR board is made up from and also the closed cell structure of the board. And here we have another torch just to add to it, you know, to see how much we can actually give this board. So later on... [Shane Clarke] That's a pretty graphic illustration there, isn't it? We weren't quite brave enough to try this with EPS. [David Kan] Yep, so this will take time to settle in. And later on in the webinar, we will come back to this to see how it's going. Back to you, Shane. [Shane Clarke] Yeah, no, excellent, mate. Like I said, it's a great illustration. Rather than me trying to explain it, let's just show a video. No, I'm looking forward to coming back to that later on in the webinar and see where we get to. Cool. So I also noticed not only is it charring, but it's also not melting either. It's another great property of the PIR board. And another thing to bear in mind is not all PIR boards are created equal. So this video and this test is very specific to the Enertherm PIR. Cool. So we're going to go move on to our second myth now. We're going to get Peter Mills to talk to this. Now, this myth is all around about vapour barrier. And in the Enertherm warm roof system, we specify a true vapour blocker. It's an aluminium foil faced vapour blocker. And regardless of the climate, climate class, building type, we specify a foil vapour blocker in our warm roof system. And it's a common misconception out there that we're seeing that it's not required. So after you, Pete, let's talk to that. [Peter Mills] Thanks for that, Shane. Yeah, we do get asked by a lot of suppliers if they do actually need a vapour barrier. This seems to be because of a little bit of misinformation out in the market. Some other companies suggest only using vapour barriers in Zone 3, which is towards the South Island. Unfortunately, water vapour occurs in buildings all around New Zealand. Now, it's our experience and use of our hygrothermal analysis software that vapour barriers should always be used. And what we'll do is we'll cut to our next slide, which shows you a snippet of this software. So what we've got here is a buildup of our warm roof on metal tray. From the bottom, we've got our metal profile, our vapour barrier, our insulation, which is 80 mils of Enertherm PIR, and then our two layers of modified bitumen membrane. Now, in blue, you can see the vapour barrier there. It's doing a good job of keeping things dry. If we cut to the next slide, we've removed it. And what ends up happening is condensation forms just under the membrane. As water vapour is allowed to drive up, it changes temperature and it condensates. Now, this happens whether you've got our metal tray, whether you've got plywood or concrete. It's not worried about what kind of substrate you're using or if you're taping a metal tray. Regardless, it still moves through and forms condensation. If you've got an alternative simulation or if you're manipulating values to the point where you're convinced you might not need a vapour barrier for that project, that's great. But buildings use cases change over time. Houses might have new spas or baths put in. Some buildings get completely converted. So, for instance, the gym I go to was a storage warehouse, so it wasn't designed for having lots of people sweating in it. They had to undergo a lot of conversion, adding vapour barriers and insulation to the underneath of the metal. And it's still not as effective as if the warehouse was initially designed to have all of those purposes built in. So that's part of the reason why we suggest in every build to use a vapour barrier, just for those contingencies. [Shane Clarke] Excellent. And just for that tiny wee bit of redundancy, I mean, what sort of costs are we talking here that we're adding to our build up? [Peter Mills] Well, Shane, it usually costs about $12 a square metre to add a vapour barrier. Given the cost of other elements in a build, this is a very small amount to prevent moisture from affecting the health of the building over time. Excellent. [Shane Clarke] So just to recap on that, we make sure that we have a vapour barrier on every single one of our urethane warmers. And Pete, is it true that we don't actually class the metal tray itself when we do the Nuratherm system on a metal tray? We don't class the tray itself as a vapour blocker? That's correct, Shane. In a two-dimensional diagram, it would work, wouldn't it? [Peter Mills] On paper, if you manipulated the values to show that a metal tray was a vapour barrier, sure. But in practise, the metal tray ends up getting holes in it or somebody misses a tape in between joins. And so what we do instead is, in the software, we count the metal tray as allowing vapour to flow through. [Shane Clarke] OK, nice one. Excellent. All right. I'm getting some questions coming in from the field. That's fantastic. Keep them coming. We've got about six to eight minutes towards the end there. We'll rip through the Q&A. So by all means, please keep them coming. We're now going to jump to our third myth. I'm particularly passionate about this one. Avoid warm roofs as they cost more than cold roofs. Yeah, I'll leave it up to the guys to debunk this one for you. [Peter Mills] OK, so this one's been going around a while. We had a report done that looks at the cost of building a cold roof, which is what you can see on the left here, and warm roofs, which you can see on the right. Now, if we look at the plywood cold roof on the left as a base mark, we then looked at our warm roof on plywood, which happened to turn out a bit more expensive, about $50 a square metre more expensive. But then when we take that same system and we put it on the metal tray that you can see on the right, it ended up $50 per square metre cheaper than the cold roof. Now, you might be asking, well, how did that happen? Well, there's two main reasons, right? The first is that metal tray can have much wider spans than the plywood roof. The second reason is that the metal is cheap to produce, and it's very fast and cheap to put down. So it ends up saving a lot of cost there. You might be asking, well, why don't I just do a cold roof on metal tray? Well, the membrane needs a smooth surface, so that's why we put it on top of the PIR only. In some cases, you might not be able to use the metal tray. It might come in a bit more expensive. That doesn't mean you should look away from the warm roof, because there's other costs that need to be considered that aren't always considered when somebody is just looking at the material cost and instal for the roof alone. So, for instance, in the cold roof on the left, there's lofted insulation that could be taken out entirely when you're looking at the warm roof. Or on the top of that cold roof build-up, you've got a ventilator there. Now, these get used a lot on cold roofs because, like we mentioned before, vapour occurs in every building, right? So it rises, it hits the top of the roof, and it needs to either escape or it will condensate and affect the health of the building. So in cold roofs, they end up being these mushroom vents, which actually cost a few hundred dollars each to instal. And that's a cost that's not necessarily thought about when people are looking at cold roof versus warm roof. In fact, when we did the analysis that looked at all these costings, it didn't actually factor in the mushroom vents in the cold roof compared to the two different warm roofs. So in our next slide, we've also got a look at the aesthetics, right? So the one on the left is a cold roof, and you can see the little mushroom vents poking out of it. The roof on the right is a warm roof. Aesthetically, there's already a very clear difference between the two. [Shane Clarke] Excellent. And we've got some actual live, I guess, live fire data, haven't we, on warm roof versus cold roof costings and things like that? [Peter Mills] We do, Shane. We've still got the report that looked at the different costings, and I believe we're available to send that out if people are interested in that. [Shane Clarke] Excellent. It's something that comes up very, very regularly. I had one down in South Island last week where a QS had really overshot it. I think it's just an education process. I don't know. Do you have any idea from the feedback that you guys get as to why people all of a sudden overshoot the pricing on it? Is it unknown, or what do you think? [David Kan] How about you, David? It's more for when it's, I guess, still relatively new to the industry, given that we've had membrane roofs for many, many years. And especially in the South Island here, we tend to have a lot of people doing what they've always done. And it's just one of those things that it's creating some more education and getting it more out there in the marketplace. [Shane Clarke] Just in your previous slide there, Peter, you showed you applied a two-layer torch on the membrane system on top of the warm roof. Have we got the other options there, if that's not the specified sort of design? [Peter Mills] Yes, we do, Shane. Warm roofs aren't just limited to modified bitumen. We also have a single-layer TPO membrane, which is glued down to the PIR and then is welded together with a hot air gun. [Shane Clarke] Would that make the warm roof build-up more expensive, or would it be about the same? [Peter Mills] It depends on what kind of quality you're going for. The way we do it makes it slightly more expensive. We use a fleece-back TPO whenever we're using our membrane, which means instead of being thinner, it's got a little fleecy layer underneath it. And the reason why we do that is that it won't show up any of the joins in the boards or any of the fixings, so it ends up being really visually quite good-looking. [Shane Clarke] Right. Nice one. We've got a few more questions on that, which we can get to in the Q&A session, so I look forward to that part. I think we're up to myth number four now. Again, talking about things that are relatively new to New Zealand, but not the rest of the world. Something that you guys get regularly is a Codemark is not as good as a brand's appraisal. What's your thoughts on that one? [Peter Mills] Yeah, this one's definitely a lot of misconception. Council will frequently ask specifiers for a brand's appraisal, and the attitude seems to be that, well, if council are always asking me for the brands, then I should just send them the brands because that would appease them. But it's not quite the case. They seem to shy away from Codemark for some reason. If we look at this next slide, this is a graph by brands who have listed the different forms of compliance demonstration, and they've put Codemark right at the pinnacle of this graph, above their own brand's appraisals. Now, there's a very good reason for that. It's that Codemarks have to be accepted by council. They can't disagree with them. They can RFI them, you know, they can request for further information, but they can't say no to a specification with a Codemark, but they can do that with a Branz appraisal. Other key points about the Codemark are for things like design flexibility. So if we look at our Nuraply 3PM modified bitumen system that was featured earlier, it has a Branz appraisal and a Codemark, and there's two massive differences between them, right? The first is that with the Codemark certificate, if you're specified with that, the falls could go down to 0.73 degrees on the roof. If you specified it with the brand's appraisal, you could only go down to two degrees on the roof, which is E2 AS1 standard. That's what council typically looks at when they're looking at a roof. The second major reason is that we have different details to E2 AS1 with the Codemark certificate. So we've got small bits and pieces that allow for greater design flexibility that wouldn't be allowed if you were only specifying with the brands. Now, not all Codemarks are the same. Some people, some companies base their Codemarks on their Branz appraisals, which kind of doesn't do too much aside from requiring the council's consent to it. But ours has a special one that's standalone. So we can end up adding all of these nice features into it that let people do a bit more with their design than they could if they were only using the brands. [Shane Clarke] Excellent. So who issues Nuralite's Codemark? [Peter Mills] That's a great question. So our Codemark is issued by Bureau Veritas. They're a very large international company which do a range of different works. In fact, our manufacturer, IKO, they use Bureau Veritas for different portions of their factories. So it's the same company from the manufacturer all the way through to us. [Shane Clarke] Yeah, right. Nice and tidy. I'd be quite keen to hear from anyone out there on their experience with Codemark. We've seen it basically change the way flappers get consent. Now, Peter touched on the fact that Codemark must be accepted by councils, which is good for the specifier, but there's a swing back there. It's actually good for the council as well, because if anything should go awry with a Codemark certified product, there's no comeback on the actual council. So it works both ways. That was the design of it. Yep. Cool. What myth are we up to now? Number lucky number five. Excellent. So myth number five, David, this has got you written all over it, mate. Apparently, people say you can't float a deck over a warm roof. [David Kan] Let's see if we can make it five in a row, Shane. Nowadays, when we're creating a waterproof deck, we do need to have access to the membrane for routine repairs and maintenance. So this is where Nuralite can offer a number of really good solutions, not only for a cold roof, but for warm roofs as well. So how can that be? This is because due to the compressive strength of our PIR board, we're able to use it in this manner. And this is within the scope of our Codemark, and it's already been approved around the country by our regional councils. Just a couple of figures here for you. The compressive strength of the PIR board is 175 kPa. And so what does that mean on a warm roof situation? It translates to the Nurajacks being able to take 600 kilos per point loading. So that's a lot of weight when you multiply the Nurajacks out. Now, the really interesting thing about our PIR board is that it can come in a pre-tapered format. You can see on that render the tapered insulation board there. Now, this means that you can actually form your falls and insulate at the same time, all in one, which is just fantastic. And the render is actually showing our two-layer torch on, but as Peter alluded to before, it can be used with our TPO single membrane. Yeah, so that's something on that. [Shane Clarke] Brilliant. Look, we're really mindful of the viewers' times. We don't want to drag on and on and on, so I'm really quite keen to nail this down to the 30 minutes we definitely promised. Now, I think we're going to flip back to the rest of your video, David, and have a look at this PIR board and see what's happening here. [David Kan] Yeah, so we've continued on here with the torches, giving it a really, really good dosing from that side. But as you can see from the other side, actually put your hand up to the other side of that board. Now, the thickness on that board, Shane, where are we at with that? [Shane Clarke] Yeah, I think we used a 50mm board on there, and obviously we can see that the flame's stopped on the other side and the heat hasn't actually transferred through. And that's some pretty intense heat from that gas torch. Excellent, I say. Yeah, like David said, the picture says a thousand words. There's the video. Like I said, we were too nervous to try it with EPS, so we didn't. All right, we're going to go to the Q&A section now, guys. So be prepared. All right, I've got a question here. Anyone of you guys can jump in and grab this one. Why doesn't aluminium foil on the PIR board act as a bake barrier? That's quite a good question, seeing as we've shown a really good image of the PIR board with foil all over it. Why don't we just use that as the vapour barrier? [Peter Mills] I'm happy to answer this one. It's a similar situation to asking why metal tray doesn't act as a vapour barrier. In theory, it should block vapour, but what ends up happening is there's small breaks in it. Not every join in the PIR board is going to be taped correctly, and in fact a lot of the times they are mechanically fastened down. So it's better to have an underlying vapour barrier than to try and rely on the PIR to do that for you. Excellent. [Shane Clarke] Yeah, because obviously the boards come in set sizes. It doesn't cover the whole roof area, and then we're going to go and put holes in it when we mechanically fix it. [Speaker 4] Yep. [Shane Clarke] Okay. I've got another quick question here. Okay, this will be interesting. I got this one last week. We'll see how we go. What happens if vapour forms in a warm roof? So say there is a breach for some reason, some mechanical damage, and moisture does get into that folly envelope sand we've created. What happens to that moisture? [David Kan] I can take charge of that one there, Shane. So if it is determined that there is possibly moisture in that area, then we can locate that area and instal a vent, as Peter was talking to earlier on, and that vent will actually be installed and vent out any excess moisture in that area. And a deemed time, it's not finite, that it can be removed and patched over. [Shane Clarke] I think the secret to the success of that vent is the fact that the base sheet in our Nuratherm warm roof is vented, so we don't fully bond membranes. So Peter touched earlier on the fact that we use a fleece-backed TPO that allows vapour diffusion. The base sheet's not fully vented either. It's actually stuck in a diamond pattern, which allows any entrapped moisture to escape through that vent. I mean, if you had a membrane that was fully bonded, you put a vent in, the moisture just can't get to it. So it's great to have that sort of added level of redundancy, isn't it? [David Kan] Absolutely. [Shane Clarke] I've got a quick question here. I think it's a really good question. We're sort of talking internally here. We all know what we're talking about. What does PIR mean? [Peter Mills] So PIR stands for polyisocyanurate. It's quite a mouthful. Basically, it's a formulation that creates rigid insulation. It's a bit similar to EPS being extruded polystyrene. But it's a completely different material. [David Kan] Excellent. Just to add to that, the PIR is what they call a thermoset material, where once it's formed, it'll hold its shape even under conditions, as you saw, under a flame, versus thermoplastic insulation products will sort of melt into molten droplets under the hotter conditions. [Shane Clarke] Excellent. All right. We've got a couple more questions here we won't, unfortunately, get to. So what we'll do is when we send this out to all the participants, we'll actually provide a Word document with all the answers there so we can all see what was asked and answered at the same time. Bit of a wrap-up here. We've debunked five myths that we get frequently asked from the frontline staff here. PIR boards, they don't catch fire. They're not classed as non-combustible. However, they don't catch fire. But bear in mind that not all PIR boards are created equally. Some people say vapour barrier is not required. Possibly, if you manipulate the software enough, you're probably right. However, we insist that you have one, just the added redundancy for an extra $12 a square metre for an asset that's supposed to last 100 years. It's a no-brainer. Myth three, avoid warm roofs as they cost more than cold roofs. Well, we've debunked that many, many times. David touched on the fact that warm roofs are new to New Zealand. Well, 15 years? They're starting to get old. They're actually starting to become the norm. So we really need to do more of it. Codemark is better than a Branz appraisal. Sorry, what did we say here? Not as good as a Branz appraisal. Okay, it's actually vice versa. Branz even issue Codemark certificates themselves, which is the pinnacle of building acceptance. And then David touched on the myth that we can't put a deck over a warm roof. Now, we can using the fully Codemark certified Nurajack system over the PIR board, even, if you like. All right, we're going to quickly wrap up on a quick poll. If you want to rate our presentation today, we always want to improve it. So please give us your comments. And then, what have we got next week? Next week, we're talking about tanking, best practise tanking for underground. We've actually got some new news to share with you there. We're really looking forward to that one. The next webinar after that, we'll be talking about the Nurajack system and creating floated decks. And then the third webinar we've got after that is the principles of passive health design. And obviously, we'll be talking a lot about isolation and things like that. All right. Okay, and we're just going to finish up with the third poll, as if you'd like a follow-up from anything that we've talked about today. We've got a team of hungry tech reps here that were keen to help you out if you think that comes up. All right, hey, thanks very much to the panellists today. Thanks to the people working hard in the background making the tech work. I appreciate it. Thanks for participating. And making your donations. We'll make your donations on your behalf to Riding for the Disabled. Enjoy the rest of your day. Thanks very much, guys. Cheers.