Types of Protection? - Diving into BS8102:2022

BRENDAN:

G’day everybody, great to have you on board! Thank you, everybody who's joined and still joining. We’re hoping for a great event. And I’ll just share the screen and we'll get ourselves going here. Give me about 27 seconds!

So just to run through very quickly. on housekeeping. I’m Brendan, with me today is Hayden, Christine, Alex. And we'll have them introduce themselves as they come on board. As to housekeeping, you'll find a comments button in the bottom right and a question and answer field for your questions. We welcome you to use those. This is an interactive event, and we'll do our best to respond as we go along. Here’s our speakers and you'll also see them on the screen!

And we've been here before. For those of us who have been with us on this journey. This is the third of a series on basement waterproofing to British Standard 8102. Today's agenda: We’re going to recap the conversation so far, and we're going to talk about types of protection in the context of the Standard - that Standard being British Standard 8102, as we mentioned. And then of course moving on to application of different types of project.

I would say right up front, this is probably the most in-depth part of the series, and we're not going to go too deep on it. We're going to try and give a bit of a drone view. As soon as you get involved in specific project questions, it does go very specific in response. But no doubt as speakers will touch on that as we go along.

Submit questions, as mentioned there’s a questions button, there's a comments button. And let's have a quick poll, everybody, if you could please tell us: What's the biggest challenge you've experienced with your waterproofing projects to date?

Thank you to everybody that’s said ‘Good morning’! Yes, a very early morning to those joining us from Perth. Throw it in there, people, as we go along. I won't hold up the proceedings at this stage, but we would like to hear from you as to what you've experienced along the way. And we're getting a couple of good responses in there already. Not understandng the products. Certification to RBS. Longevity, longevity of the system, that’s a very crucial one. So yes, I think these things will come up as we go through. Without further ado, Christine, could you take us away on a recap?

CHRISTINE:

Yes. kia ora everyone. Thanks Brendo. As Brendan mentioned, this is a big topic, and we know that we've got people joining with a wide variety of experience in this, or awareness of BS8102.

I'm sorry! I'm Christine, based in New Zealand, and I just dove straight into it because I feel like we've all been here before! But I'm sure there are some people joining new. But I work in the design and specification side in NZ. And so yes, we're going to be going over this, as Brendo mentioned, in a bird's eye view scenario. So we're going to touch on each of the areas. But there is a lot more to talk about and a lot more to understand. So do get in touch if there's specific things you want to ask us.

And in terms of what we've talked about in the previous webinars, if this is the first day you're joining us, previously we talked about what the British Standard is. We went over, in a Q&A session afterwards as well, about where our industry sits in Australia and New Zealand and what the issues are. The problems that we're finding with execution in terms of basement waterproofing and so why we kind of need to adopt the British Standard and what the benefits are for that.

We also dove into, in the second webinar, we dove into the ‘grades of environment’. And so grades of environment are really defined in the British Standard. And Brendo will send you the link after this, where there'll be the links to the previous webinars where we dove into that. And so those grades of environment go from your lowest level of protection, through to 3... from 1A to 3. And they're really well defined. So I do advise that, if you weren't with us for that, then you go back and watch that, because then that will help you in terms of your discussions with clients.

And if we go to the next slide, Brendan. Today we're going to be talking about the ‘types’. So ‘grades’ that we've spoken about previously, that's the level of expectation of the waterproofing. What's the waterproofing outcome going to be? And when we're talking about ‘types of protection’ we're talking about the materials that we're going to use to achieve that grade.

And so in terms of how we're selecting, we're factoring in things like risk, water table, all of those sorts of things that we have discussed before. And BS8102 recommends that if you're anywhere above grade 1A and B, that you're incorporating a couple of types of waterproofing in the system, so that there's some redundancy; so that you're not just relying on one, and then - failure is failure - that you've got some redundancy in the system.

And so in terms of the types that we're talking about. All right, just lost you all... In terms of the types that we're talking about, we're talking about Type A, B and C. Alex is going to get into this in more detail. But as a brief overview, type A: that's what you're familiar with when we refer to tanking. So we're talking about a barrier protection. We’re talking about membrane bonded to the structure. And so that’s external and there are internal type A protections as well. Type B we're talking about structurally integral protection. So where we're relying on the structure, relying on the concrete to be waterproof. And type C is drained protection. And so that's where we're using a drainage system to prevent water from getting into the space that we're using. And so that we're dealing with that water and removing it from the area of use that's below grade. And so, Alex, you want to get into each of these in more depth, that'd be awesome.

ALEX:

Thank you. Christine! Hey, everybody. Alex Portelli here from the Australian office. Very similar to Christine. I deal with all the design and specifications across AU. So be more than happy for you all to reach out, if need be, to take these discussions further after the fact. Yes. As Christine's going over the different types, you've got your barrier protections. I mean, this could be as simple as a cementitious slurry to be covering the wall etc, as a barrier from water coming into the space.

It was mentioned that bonded systems are quite important now. And this is to avoid moisture tracking into your space as well. It is important to note that waterproofing measures should be designed on the basis that, during the life of the structure, at least, water may be coming up against your structure. And by doing so, a consideration to have your waterproofing come up the side of your structure and up and over on the ground side is definitely something that needs to be looked at, as a continuous system, if you will.

In saying this, it does become a part of the design and what is actually required for your structure when it comes to waterproofing, as it may be necessary to use a combination of types. You know, your Type A mixed with Type B; or Type A with Type C; Type B with Type C, etc, etc. Really comes to what is necessary to ensure your space is waterproofed. Another way in doing this in a very effective way is by using ‘Figure 1’, which is in the design flow charts of BS8102; which really gives a great overview of how the different areas can all collaborate together to ensure we're all meeting the criteria, and the design is fit for purpose – which I think is quite an important step. Are we able to to move across to the next slide, please, Brendan?

So with Type B, as Christine mentioned, it's structural integral protection. So using the concrete for its intended purpose, to avoid water coming into your structure. Now MARKHAM have been completing this Type B waterproofing system for over 20 years now. It can be very cost and time effective, within the project, as you're waterproofing the structure, or tanking the structure as you, effectively, are building, doing your basement. And it's not a one size fits all. So, as I said before, it could be a combination methodology, if that's what the site needed. But it's definitely something that MARKHAM has been doing, and we find it a very friendly way to incorporate it into a project, should it be fitting the design requirements.

Next slide. So moving into your Type C with your water management system here. It's a good option when the risk is low. Typically used in conjunction with Type A or B to safeguard and ensure that the internal space is protected. Now when it comes to type C water management, there is some ongoing thought processes that need to be, you know, discussed at the beginning of the project.

And that's to do with ensuring that the system is kept in an operating fashion. So access points need to be designed in, so that they can be periodically checked, and ensured that they can be flushed and maintained so that the water does have an effective egress path out of that design and drained system, so that, you know, it doesn't affect your internal space, as the project progresses in its lifecycle.

Moving to the next slide - shooting over to Hayden now.

HAYDEN:

Thank you, Alex. Hello all! We've all been here before, I think, as Christine mentioned. So it's good to have many returned names on the screen. That's great. Thanks for joining. That's interesting. But I firstly want to point up: the success of getting the right outcome in waterproofing is, determining those ‘grades’ that Christine mentioned.

I just want to reiterate this on this slide. So before we get to selection and application of what ‘type’ of waterproofing, we really must be strong and united on what outcome we want, what performance grade we want, and what level of protection we want. What do we want it to look like? And that's first and foremost in everything. Now, one thing to consider, different areas of the structure or a building might have a different performance grade set for it, due to, you know, what's inside. Or they might be on a slope where you've got, you know, more risk on one side, etc.

So that's very important when we’re on waterproofing, and that determines if we choose the Type A, you know, where we’ve got a physical barrier against the water; or the [Type B] structural waterproofing, like Alex was just talking about, inside the structure itself; or that [Type C] temporary approach with a drain system. So it's...

I just want to reiterate that because I think that's the space in our market that we're not doing enough of, is determining that, working out that at the start. The rest almost flows easier when we've got that clear. So this here is a bit of a table in BS8102. It's probably a little bit hard to understand. What it's trying to say is, where we’ve got low risk, you've got obviously more options.

You've got the Type A, it’s very much an acceptable approach. That’s the physical barrier. Type B, where we’ve got the structure itself, is acceptable, you know, with some conditions. You’ve obviously got to get it right, get your methodology right. And then Type C, as stand alone, is acceptable when you've got the system right. Now in Australia, New Zealand, we've been very, prone to just do wet-wall basement, and bring the water in and deal with it inside. That's a totally different space. We would not recommend that, where you've got open drains etc. Type C cavity is - OK, that moisture is still coming in, but it's not seen. It's dealt with. You've got systems in place to get rid of it, and you've still got a very usable space inside. So when you've got a low, very low, risk associated to the water table like this is showing...

Now we’ll just jump on that for a second. Low risk for water table, as in BS8102, is when the water table is permanently below the underside of the slab - the ground slab. And the high risk is when it's permanently above the underside of the slab. So we would see a lot, if we take that, we would see a lot of projects in our areas that would actually be higher risk than we think.

So this here is essentially pointing through to say a Type A barrier system is your best approach. But very... for measures to reduce risk is we need to start thinking about a combination of systems, and what can be incorporated to get that best outcome. So hopefully that makes sense. It's establish the risk, establish the performance outcomes you want and then go through the phases of what's needed.

You might in some instances have a variable water table. And that's where you need to think about, you know, what can build up over time, etc. Make sure you got the right protection there. So hopefully that makes sense. Jump to the next slide. And then combination of systems. Now this is interesting and probably not widely used in our regions compared to what the British Standard in the UK is doing, which is good to follow. So it's established once you, you know, your high risk basements and then you’re obviously wanting to use the space etc. It's very unlikely that a single system will be sufficient. We still probably think that in our design process that, you know, we can just put a system through. Type A or Type B. It's enough. It's a very good push to get a combination of systems.

Now, a few things to consider when we've got a combined system. We need to think about the characteristics of the products being used. So it's not like just getting two tanking membranes and putting them on the side. That's not a combined. It's talking about having, like, a flexible type approach on the outside and a rigid system on the inside.

Something that... The key thing is that both products won't be subject to a common failure. Say we have seismic in New Zealand, or those sort of conditions. Or concrete cracking etc. Make sure the two products are compatible, for a start, but then also working differently in characteristics, to make sure you got that cover over time. And then just to touch on what Alex was saying too, combined systems, make sure it integrates with your continuity of waterproofing. So yes, up, which is 150mm above ground level. So those are some things to think about there. But this is really to reduce your risk and deal with... mitigate those issues as early as possible. And next slide.

Then remediation. Now this really needs to be... We’re spending a lot of money on remediation in Australia and New Zealand. And we need to spin that round. We really need to think about strategies for remediation at design phase. And this is outlined quite nicely in BS8102, and it's a very good measure, when we're going through design phases and our early work, desktop studies etc, to make sure we're getting the right systems, the right outcomes – that we’re thinking about the remediation. Are we able to get back to those, you know, points where we need to, if ingress comes in, if we need to remediate?

Now Type A, which is the barrier, physical barrier - and we often see that on the earth side of the concrete - obviously in that space is very hard to remediate. Obviously a bonded membrane is very important now because otherwise you just get tracking behind those membranes and you get the remediation. Everyone’s probably been there, where you've chased cracks for the life of a project.

The Type B, which is the integral waterproofing. That's usually the most isolated, you know, failure area. And you can hit that with injection or, you know, slurry coatings, all those type of things. And it’s isolated, that's probably the easiest as far as remediation.

And then cavity systems are very good. But it's not really the failure of the system. It's more that you'll be checking things like your pumps and all your drain, your hobs, etc. All your drain systems, are they blocked? Are they clear? Have you got a maintenance program to make sure your water is flowing? Are your pumps, all the electric components etc protected and checked? Those sort of things that are remediation for a cavity system, which is Type C. So the big point there is, make sure that's thought about when you're going through your design phases.

So hopefully that makes sense. And we do really want to prompt questions now because that's the... We've touched on this, as Christine said, in pretty light detail. There will be a bunch of questions in all your heads about what's the differences? When do you use one? You know, or what type of barriers there are? Etc. What’s, you know, Type A? We're really pushing on the bonded membrane phase, versus a flexible, for Type A. So there’s BS8102:2022. It's very good. I’d recommend anyone to get a copy that's interested, in this call. There's probably about 25 pages, almost, that just go over the A, B and C system, the types of barrier protection within that, the types of structural protection. What needs to be considered and what needs to be undertaken.

So again, Type A: barrier, physical barrier. Type B, you're working with the structure itself. And then type C is a cavity system or water management system that's coming into the structure. And then the combined system is very much a consideration, and should be considered more. Now, just one more thing on that. If you’re combining A and B - that's like a barrier and integral - the Type A does need to be a bonded [membrane]. So that's important. So hopefully that summarizes what we have been going over to see some questions coming in, which is great.

That probably pretty much segues us into the Q&A Forum! So we'll open up the floor. No doubt there'll be some good stuff come through. Christine, did you want to touch on any of the comments that came in earlier? About longevity of systems, and it probably touches a little bit on the remedials and things as well.

CHRISTINE:

In terms of... I can't see anything in the ‘Questions’. Everyone's writing in the ‘Chat’. Is that right?

HAYDEN:

Yes, sorry.

BRENDAN:

Yes, that's fine.

CHRISTINE:

I was just hoping that it's not my computer lagging. No, there was a couple of things there. One of the things - that I know we've mentioned in previous webinars as well - is when we're assessing risk, not to just design to where the water table is currently, but that BS8102, the new 2022 version, it is also talking about massive flood events.

So if a drain bursts, the rainwater drain bursts and things like that. So you've got to think about it right the way out. Not just, where is the water table now? Where does it fluctuate normally? - But, Where could it get? So I just want to reiterate that again. In terms of... Oh, Mark you were saying - that was in response to, What's your biggest challenge? - is that the longevity of waterproofing systems is your biggest challenge.

So in terms of that, you do want to select... you want to be making those inquiries at selection stage as well; in terms of, What's the life of this waterproofing system? And also, How long can I expect it to last without maintaining it? Or, Who are we going to be handing this building to?

So especially in a Type C scenario, you're going to want to know that there's a continuity of responsibility for looking after and maintaining something like that. Gosh, now there's things coming in thick and fast!

Mark - the copy of BS8102, you should be able to locate that. We can’t send you a copy. It's got confidentiality things written all over it. So you'll be able to find that online fairly easily. But I'm sure that Brendan can include some link or...

BRENDAN:

Yes, I’ll include a link. It's a licensed document so I’m afraid we can't just share it. So yes, we’ll make sure there's an access link for that.

HAYDEN:

A good question from Samson. How do we how do we cater for... [BAL] I'm taking it that’s bushfire related?

CHRISTINE:

Sorry, I don’t know that one.

HAYDEN:

Yes, slowing down the Bushfire Attack Level or something, I think it is. Is that right? The install. So it's important; and it is important to consider that when we've gone through the design phase, what types of protection are needed, because it may be better when you've got a structural Type B, you know, that the structures working; and then a cavity inside to deal with it, you know, versus a membrane that's left exposed and on the outside and that might have risk to that over time. So it's a good question. As far as slowing down the install, it really does come down to the type of protection we are putting on, really. But hopefully that makes a little bit of sense.

CHRISTINE:

There was Heber’s comment about getting the joints right, is a challenge. In that probably... obviously there's a few things to consider depending on what system. I know there's a challenge in New Zealand with requiring the earthquake movement joints in basements, which is a relatively new introduction. But in terms of getting the joints right, I think again, that comes down to that really early planning, bringing the waterproofing design into the early planning stages as well, so that that sort of challenge is considered from the get-go when people are making decisions about how the structure is going to be built, that we're going to need to waterproof it as well. How about we iron that out early.

ALEX:

Tony’s comment on rigid systems, rigid barrier systems to remain intact with seismic movement. That would come down to early discussion selection process, ensuring that, you know, the barrier system chosen was going to be fit for purpose in that particular space as well. I mean, as we've mentioned across the board, this definitely isn't a “one size fits all” methodology, and considerations have to be taken, in conjunction with design practicality and longevity as well. So, that would probably cover off that one, I presume.

HAYDEN:

Yes, I was looking at that, it's a good question because there is a lot of different barrier protections in Type A.

ALEX:

Yes.

HAYDEN:

Some are very rigid, as in, like a cementitious coating...

ALEX:

Yes.

HAYDEN:

...which would obviously crack with movement; versus a flexible membrane that gives you more to play with. What you do have to be careful with a little bit is - and there was a question there about how much seismic movement can be sort of tolerated - but that's a very hard one. Everyone says their product has ‘x’ amount of elongation or whatever it is. But when you've got a bonded [membrane] on, you know, both sides of a crack, you've actually got no movement, right? It becomes part of the structure. So just be careful when you, when you're considering that, is, how much tolerance it can be. And make sure we get something solid from a designer on what can be dealt with.

ALEX:

And that sort of touches base, too, on the combination of systems as well. You might want to design in your Type C, as well as your Type A bonded system there, in the sense that if something were to fail, for example, you do have that ingress of water if it were to come into the space. So that's what we were talking about with those combination style designs, to make sure it's facilitating exactly what's necessary.

CHRISTINE:

Going back up the chat again, I'm just making sure we're not missing anybody. Shane’s challenge in terms of leaks after the fact. BS8102 does go into reasonable detail about approaching remediation, and also anticipating remediation; which is a really nice inclusion, because we know the reality of a perfectly designed system works great in theory. There are site challenges. Things happen. You know, there are workers on site. There's different substrates that we weren't expecting, things like that. And so it does take into consideration that remediation might happen, might need to happen during the construction and early on. So, it does really have that expectation. So, there are different ways to approach the different things that Hayden was talking about before.

HAYDEN:

Good question from Mark regarding, Is it realistic to ask for 50 years to protect the structure? It is; and what you need to be careful of is, you're asking for a performance warranty, which incorporates a full system. And OK, that will determine how it's designed, what type of products go into it, you know. Is it Type A, Type B, combined, Type B / Type C? Whatever it is. But with what's available now and if you do the process right… So right at the start of BS8102, it's got a good flowchart of the process. So a big portion of that is the desktop study. And you know, all your geotech and your soil types and your water tables etc. If you flow through that correctly, it's very… I believe you're able to ask for that 50 year protection.

ALEX:

Yes - all things considered, right?

HAYDEN:

All things considered, yes. Which does go obviously right through to how it's managed on site. Everyone having the same view of what success looks like. Right from designers to installers, etc.

A good one from Simon with the Meso system, a lot of people will be familiar with that, which is steel shored piling. Yes, we have. We've done projects there, which is good. But it's interesting that in BS8102 it actually now recognizes steel shoring to be as a barrier. So that is almost like a barrier membrane. But you'd still need to combo it with something because you're not, you know, guess you're not getting full protection with that.

But yes, there's two... or there's a few ways of doing it. Obviously [could have] a membrane on your shoring and then you pour your concrete against it. Or simply admixture, structural integral system. So admixture and water stops, in the concrete wall in front of the system.

BRENDAN:

Do you want to talk about the... we got a question from or a comment from Loch, on drainage systems and water collection pumping points. That touches on what we were saying about the Type C earlier.

CHRISTINE:
Yes, there is mention of that specific issue in BS8102 as well. And potentially the requirement to treat the concrete, coming up in contact or near that drainage system, to prevent the calcium hydroxide leaching out and creating the salt build up in that system. So that is something that is discussed in the document as well. It's not too specific, but it does mention that as something that can be a requirement to be addressed.

BRENDAN:

That's fair enough.

HAYDEN:

I think a key point of the cavity system would be the... Well, all the systems really. But the regular maintenance schedule is very important. And that should be designed with the structure itself.

That's good. Good question.

BRENDAN: Very good questions have come in.

HAYDEN:

I’m not sure if there's any more popping through... have we missed anything, Brendan?

BRENDAN:

I think that is about it. We appreciate everybody's involvement and interest. Thank you very much! As noted, we will share the links to the previous sessions on the follow up email and hope you can give us some feedback about what we did right and what we did wrong, and what you'd like to see next time round.

CHRISTINE:

Thank you.

ALEX:

Thanks everybody.

HAYDEN:

Thank you.

BRENDAN:

Excellent!