Unpacking British Standard 8102:2022 - Part 1

BRENDAN: Good morning and good afternoon, and welcome everybody! Thank you very much for joining us today for MARKHAM’s webinar, our latest online event, Unpacking British Standard 8102:2022, and how it applies to Australia and New Zealand. As you’re aware, we have had some changes with personnel along the way.

We’ve taken the opportunity to break this topic into two parts, partly because it’s very popular – the take-up on the webinar, for which we thank you all, and partly because the topic really does have a lot of moving parts to it. So we thought we’d, as I said, take the opportunity to break it into two sections. This is part one. The other session will be on the 30th as part two. And without further ado, we will launch into it.

So we’ve got Unpacking British Standard 8102:2022. In part one, we’re going to talk about: what does it include, and how is it relevant in Australia and New Zealand? With us on the call today, we’ve got Hayden Prestige and Christine Melville. Hayden has been with MARKHAM for about 10 years, has a background in construction, and one of our most experienced team players. Christine is also quite experienced in the spec space, in particular, for architectural engineering, and looks forward to presenting this to you.

Is everybody hearing me all right? Could you perhaps just pop on the chat to just say yes, just to confirm that you can hear okay? All good? Thank you very much. That’s excellent. And now we’re just going to have a very quick poll on the chat. If you could please tell us what’s your role in the waterproofing industry, if you’re involved in the design or consultancy space or actual construction? Building surveyor, documentation. That’s excellent. Inspections, very good. Project management. Very much appreciate that. Keep them coming in. We’ll try and do our best to tailor the presentation to your needs.

So, very briefly, the learning outcomes. What is the British Standard 8102:2022, and why is it significant to the construction industry in Australia and New Zealand? We’ll talk about the grades of environment, or the levels of risk. We’ll talk about waterproofing protection types. And very key to this is ,we’re gonna talk about the importance of early engagement. So, Christine, could you please take us away?

CHRISTINE: Kia ora, everyone! Thanks, Brendan. So to kick it off, what is BS 8102? I’m sure a lot of you are already have a range of familiarities in terms of that. But what it is, is the British Standard for Protection of Below Ground Structures Against Water Ingress. It’s been through an array of titles over the years, and this last one is intended to capture the intent to waterproof below-ground structures, not just from groundwater, but from any ingress of moisture coming through. So yes, as it says, it’s a code of practice. It’s a guide. In terms of that guide, Australia and New Zealand are influenced by this, which we’re going to get into in the next slide.

So yes, in terms of its significance in Aussie and New Zealand, they’ve been operating under this standard for a significant amount of time in the UK, and we’ve been influenced by that. And as part of that whole holistic way of looking at it, it means that it’s incorporated early in the design and brought in. Before we’re even considering what sort of structure and how we’re going to create that, we’re going to look at the waterproofing as part of that holistic response to looking at the waterproofing strategy. Have you got anything else to add to that, Hayden?

HAYDEN: No, that’s perfect. Hello, all. It’s awesome to see everyone on board today. No, that’s good. I was just going to mention on that one, for those in Australia that have joined us, the NCC that’s coming out next year, obviously there’s some changes in that, if everyone’s familiar or not. But there is some classes of buildings that haven’t been recommended to waterproof in the past, now requiring levels of waterproofing. So there is quite a close connection between them now. That’s good. I think also you said, I think the British have been guided by this by 1973, through different [titles]. So yes, we are way behind on this side of the globe, and we do need to catch up. So hence why we’re here. No, that’s good. Thanks, Christine.

CHRISTINE: Yes. So in terms of that side of things as well, I’m sure you are familiar—everyone’s involved in the industry—where a structure is, thinking in terms of the cost about how we’re going build it, who’s going to build it, waterproofing can often be tacked on as: “Oh, we’re going to have to waterproof it somehow.” Rather than being incorporated, like the UK have, from the get-go. So that’s the impetus of this standard. That’s what it’s going to change in terms of, as Australia and New Zealand picks it up in a more real way, the hope is that it will then change how we go about it. So that we can spend less money on remedials and litigations and things like that, so that we can get it right the first time. So it’s an exciting thing. Any time there’s a change and adopting a new way of doing things, there’ll be headaches and barriers. So we’re going to talk about that later and get your feedback about that.

But yes, if you want to jump into the next slide, Brendan. So one of the things that is really good in terms of clarity about the BS 8102, especially the 2022 iteration, is the definition of terms, and being able to get everyone at the table on the same page about what it is that we’re talking about. What’s the goal of the waterproofing in this structure? What’s the expectation? What’s it going to be used for? So down the bottom of this page, we’ve got a couple of terms that are, once again, guided by the British standard. But we’ve reworded them slightly, just so that they’re clearer for your everyday listener.

So in terms of seepage, what we’re talking about is gradual transmission of collectible water through a structure. And when we’re talking about damp, we’re talking about slightly wet conditions. You know what a damp wall looks like. But if it’s not collectible, we’ll call that damp. If it’s collectible and it’s seeping through, then that’s seepage.

So as we go through the different grades, this provides real clarity about what the expectation is. So Grade 1A: you’ve got seepage and damp areas, both internal and external. So internal: condensation. External: obviously coming through the wall from outside. But they’re acceptable as long as they’re not impacting on the use of the building. So think a low-end basement carpark, you might have channel drains to guide that moisture away. But it’s not going to impact on the use of the carpark.

Grade 1B, the next step-up from that, is: no seepage present. So you can have damp areas, that’s acceptable to the client or acceptable for the use of the building. Plant rooms, car parks, again, that sort of thing. Then Grade 2 would be a higher-end use. It could potentially be habitable. The difference there between Grade 1B and Grade 2 is: no dampness present, but you could have condensation forming from the internal sources of moisture. Then your highest level is Grade three. So Grade 3 is: none of those, you’re going to need to incorporate ventilation and dehumidification. So thinking archival storage, and more—my mind has gone blank on other versions for archival storage, and situations where no moisture being present is of the highest priority.

So being able to establish early on, at round tables, as the building is being thought of, and using really clear terms for what the requirement is and what the client expectation is. These terms are really helpful. Anything else to add there, Hayden?

HAYDEN: No, brilliant overview. I just want to reiterate that point. This needs to be established really early, and that’s the intent of this standard is to get to that point. Because not only does it guide us through the waterproofing side of it, but everything around the methodology of design, the structure, how it’s being built, the materials, etc, need to go into that. So establish that grade and then move on from there. That’s good.

CHRISTINE: You will be taking this one.

HAYDEN: Righty-ho. Yes, I can have a crack at this. So we’ve looked at some of the aspects around what we’re trying to establish. And now, the response to that: the materials or the systems we can use to provide that protection. So the BS 8102 goes over three types. Type A being a barrier, so an actual physical barrier protection. But it is a bonded membrane, and that’s probably quite an important point for that Type A. It’s something that becomes part of the structure. I think it’s in there for the intent that tracking of water, if it gets through a membrane, is limited and can’t track to a control joint or that type of thing. That’s what the intention of a bonded system is.

Then we look at the Type B, which is integral, and that’s inside the concrete. So it’s actually the structure that’s working to stop moisture migration, such as your admixtures, your water stops, that type of thing. It’s actually in the structure. Then, Type C. Whilst we might be familiar with the terms of wet wall, etc, Type C is basically a managed system internally, by the use of cavity drains, going to a central point, pumped out, those sort of things. It may still look very nice on the inside. But Type C, you’ve got to think about your structural integrity, etc, as well.

So again, just pushing that early engagement and early thought. Not only looking at the grade on the risk of the basement, but also start thinking about how you’re going to protect this structure and what type of approach you’re going to build. Because that also determines your building methodology, right through your design. So does that make sense, Christine?

CHRISTINE: Yes, absolutely. I think, are we heading to the next one?

HAYDEN: Cool, so now let’s just look at this. So some of you have been familiar with this table, it’s part of the BS 8102. Now I’m trying to explain it, and just feel free to ask questions, etc, please. Because that’s the best way to get interaction. Hopefully everyone’s following today so far. But use that question down the bottom-right. Sorry, I was looking for it. Yes, bottom-right. Just pop questions, and then we’ll get into them in the end.

So this is purely looking at the risk associated with the water table. And like Christine said, there’s a lot of other aspects going on. There’s water vapour, there’s flooding events, there’s perched water table, these sort of things that need to be considered. But looking at it purely as water table, Low being: it’s permanently under the underside of the basement slab. That’s how it’s defined. And High being: permanently above the undecided of the basement slab. So you look at a low-risk, low water table basement, Type A. So your membrane is obviously acceptable there, and in good use. Also, the likes of your integral system, your admixture type system, and also a drainage system. That’s because your water table is very low and risk is low.

When you’ve got variable, this is a hard one to manage, obviously the water table fluctuates. And we see that a lot with buildings that were okay, and then they get a building put beside them, and you get that displacement. You get that. But then also, surface water flooding events, etc, that make the water table go up and down. So Type A is still acceptable. And then Type B is acceptable, but then you’ve got to start thinking a little bit more about the building—is it repairable, can you get to the waterproofing, etc. Then Type C is acceptable. Type C is acceptable all the way through, because it’s an internal system that you’re managing water ingress as it comes through.

Now where it’s high, where water table is high, the bonded membrane systems are acceptable. Obviously, your concrete has to be, the code for us would be 3600 in Australia. But Type B is becoming less acceptable here when your water tables are up, because of that risk associated. You actually physically need a barrier. But then, real good measures to reduce your risk further, and we’ll get to this in a minute, is your combined protection. This is really brought out in BS 8102. Use of a membrane, i.e. a physical barrier, and reducing permeability of your actual structural concrete is important. Then also, your methods in place to discharge or move water internally. So hopefully that makes sense as a bit of a table. We will get these slides out as well, so feel free to request. But we’ll jump to the next slide.

Oh, this is yours, Christine. Go for it.

CHRISTINE: Yes, sure. So again, I feel like we’re hammering this one hard. But the intent of BS8102 is for the waterproofing strategy to be extremely early, so right before we are commencing design. Obviously you’d be all familiar with it, you’re doing site assessments—what’s the geology, what’s the hydrogeology, where’s the water table? But as Hayden has touched on as well, the BS8102:2022 is about establishing where the water table could be. So taking into account, structures being built next door, what’s the highest possible level that the water table could get to, and where are the flow routes for a major weather event? I’m sure a lot of our NZ people are familiar with our once every five minutes 1-in-a-100 or 1-in-500-year rain events that we’ve had around the country! So we’ve got to be thinking about those in a design sense from the get-go, and be really thorough and be risk-averse, extremely risk-averse, when designing these things. Because that is part of what needs to be proven for the BS 8102 standard system, and being guided by that means that we’re starting to adopt those strategies. So thinking about what’s the worst possible case scenario in terms of water getting into this? It’s not just groundwater, it’s not just water table. But where could this fluctuate to?

HAYDEN: Yes, that’s good. Even contaminants, or we’re building over more existing sites, etc, all those sort of things, which obviously comes into everyone’s role. So that’s good. I noticed there’s a few that were involved with inspections and consultants, building surveyors, etc, on this call. So before we jump to the next slide, I was just thinking, obviously we’d all be familiar with how much we’re spending on remedial, especially some of you in your roles. I think we really need a rethink on that in Australia and New Zealand of how we can get it right at the start. Are we running through these systems right? Are we really evaluating? Are we doing our desktop studies to really put the right method in at the start?

Like everyone says, we can’t pay for it, our build costs are too high, etc. But if we quickly ask what the remedial budget is, which is never a budget, but it’s always in huge numbers post-build. So I think we need to consider that.

If we jump to the next slide, Brendan, it’s just where we look at the combined systems. So British Standard goes over this, and it’s probably something we need to consider more as a team, in our industry, to make sure we’re getting the right approach for a project. And if we’ve gone through those design evaluations, worked out where our water levels are, worked out what the risks are, is a Type A, B, or C by itself enough? Quite often not, really.

So where the standard goes over this is, where there’s two different combinations, they’ve got to perform different characteristics. So one like a physical barrier, one integral, or a physical barrier and a drained inside, those sort of things. But you really need to start considering the risks associated, and then considering whether that one system is enough to take it out.

Now, they’ve all got their limitations in their own right. As in, bonded membrane, they can be penetrated, or something can move, they can crack, depends what the system is. Then internally, you’re relying on admixtures, relying on the structure itself. You might get cracking, you might get settlement movement over time, those sort of things. And is that one system enough? Then Type C is, you’re draining in the inside, but essentially you’re still allowing moisture to ingress through the structure. So does that bring into question your structural integrity? Those sort of things. So it’s just something to think about there, and it is a good section within this Standard to consider. Hopefully that made sense.

If we jump a slide. So just in summary, obviously, the BS 8102, and it’s important to refer to it as 2022 update. I think it was in 1973, 1990, 2009, and then 2022. So that is the important thing to consider, and making sure you’re working off that most relevant information. There is a lot of talk in our industry over here, obviously, that we will be bringing a standard in. I’m not on those standards boards, but there’s obviously a lot of discussions on that. So something to think about, the Australia or New Zealand version of this. So let’s get our head around it now.

We looked at the definitions and grades of environments, so that’s really establishing the risk and what level of performance is needed, and then the types of waterproofing that can be utilized to control that performance. Then obviously, we looked at the design thing as well. But hopefully, everyone on here joins us for part two, and this is where your questions now will be really important.

So on the 30th, I’ve got Stuart Tansey joining us from Newton Waterproofing. So they’ve been well long-established in the UK, and huge levels of experience. So it’ll be brilliant to lean on there. So we’ll look at some of the reasons around failure, we’ll look at the risk more into the risk assessment side, what needs to go into that design process, which is very early on. The use of specialist consultants, which is a lot on this call right now. And the team approach, which I think is really important, because we need to get our heads together early on a project to get it right. So hopefully, that was a good little brief insight for all.

But question time. If you can just open your questions box right now and just type in, what are your challenges that are stopping adopting this being a reality right now? What are you seeing in the market? We’d be interested. Or any other questions through that webinar would be good. Thanks.

CHRISTINE: Yes. Is there anything that you see in the way that the British Standards are suggesting we do things, that you think would be a complete roadblock in your context, with the people that you’re familiar with working with, or the industry where you find yourself. What are the roadblocks? What are the headaches?

HAYDEN: So there’s a question there from Luke. But might have pressed Send a bit early on that one. Feel free to keep typing the message, and we’ll get to it in minute. There we go.

Yes, good question, Luke. It’s a huge challenge in New Zealand and Australia, isn’t it? The use of shotcrete or sprayed concrete. It doesn’t specifically say ‘Thou shalt not use’. It’s widely used at the moment, mostly because of its speed and its low cost. But let’s be honest, the performance of it is not there. The quality of concrete compaction, the voids forming behind, you get shadowing, those sort of things. It will come to the point where it’s not the method of choice. That probably really goes into the early design part—what’s required, what grade of basement or waterproofing is required, and then how are we going to build it? That’s where things like in-situ versus shotcrete is a thing. But 100% agreed, it’s probably going to be the biggest challenge, is moving the industry thinking away from that to make sure we get a success. But interested if you have any more points or comments there, Luke? Anything on that, Christine?

CHRISTINE: No, sorry, I was just checking the chat. Because I can see that Ian is typing, but I’m not sure if you’ve just left your cursor in there. I thought maybe there was another question coming through. But yes, absolutely agree. I mean, in terms of the industry big shifts needed, if we’re going to take waterproofing seriously from the get-go.

Ian is saying, convincing the client. Yes, absolutely. So in terms of that, it really will be talking around what Hayden was discussing in that last slide about: we can spend money now, or we can spend money in remedials and in legal costs because our building has failed and investigations into how we can resolve things. But yes, if it’s a level playing field and everybody is having to adopt these strategies, then it’s going to result in better outcomes. But yes, of course, there will be some cost changes, but it doesn’t have to break the bank. Just sensible strategies.

HAYDEN: Yes, I think that’s right. It will be a challenge of the industry, getting that mindset change. I think Australia Concrete Repair Association put out, I think it’s a number of years ago now, but a dollar spent in construction phase, and in the multiple fives. Essentially, long-term of not doing it right is premature deterioration, and you could get into the point where it’s not going to last the service life that it was intended. You end up building again before its service life. So you’ve got to weigh up those sort of models as well when we’re talking about this. That’s good input. So I think that’s some good points to cover on our next session. Anything else, Brendan?

CHRISTINE: I can see Rian is typing, we can wait for them too.

BRENDAN: We’ve just got another question coming in, I think. There we go.

HAYDEN: That’s good. Thanks to everybody for taking some time out of your day. Too much appreciated. It’s a brilliant list here.

BRENDAN: Just on that one from Luke, Hayden, regarding CSSW qualification.

HAYDEN: Yes, good point. So CSSW, Certified Structural Survey of Waterproofing, I think. Have to check my mind on that one.

CHRISTINE: Survey of Structural Waterproofing. It was just [flipped]!

HAYDEN: Right, yes. At the moment, there’s only a handful in Australia, I think less than 10 off, and we have a couple in New Zealand. It’s actually something MARKHAM have partnered with a UK company as well, so we have that ability to do that design aspect and be the certified designer through there. I believe that will be coming, and will have to roll through. Obviously, there’s always a place for the waterproofing specialists, the consultants that take over the whole waterproofing, the holistic of the build. Because you can’t just have one focused on the subgrade, etc. So I believe that will be a requirement.

BRENDAN: Rian has got a challenge, is getting developers and builders to look past only worrying about their warranty period, and looking to build for the long-term performance of the building. I think they’re playing our song there.

CHRISTINE: Agreed!

HAYDEN: Yes, that’s definitely a challenge, and it is a roadblock right now to stopping a lot of this good action happening. Too many people looking at an Excel sheet with numbers, which is not a bad thing. But how far ahead are we projecting? That’s a good point. Brilliant input, and much appreciated!

BRENDAN: All right. Well, if everybody has contributed at this stage, yes, we’ll have the other event coming up on the 30th. By the way, that CSSW question, Stuart Tansey is certified, so he may be able to give you some more detail on that. By all means, please have your questions ready for that occasion. Very good. Thank you, all!

HAYDEN: Yes, thank you all. Thank you very much for taking some time. See you again.

CHRISTINE: See you, everyone. Thanks!