Cavity Barriers BIM4Housing Roundtables 23-06-2023

RICHARD A couple of years ago we developed guidance for 12 fire critical assets which we’re now looking to update in line with the Building Safety Act and the Fire Safety Act.

GEORGE (shares screen). Basically just to explain what BIM4Housing is, it’s not about 3M modelling, it’s about better information management. We’ve got 6 working groups that are interested in different aspects of the process and we try and identify what problems could be addressed if we had better information management. Each of those groups meets 6 times a year, so we’ve got 36 working group meetings each year and what we then do from those is identify particular tasks that workstreams get together and work on to come up with better data, standardised data templates, reusable libraries, the 12 critical components or asset types that we’re going through at the moment and then the information about procedures and the like.

And just to put it in context, one of the challenges is that you’ve got different people in different parts of the organisations who are interested from different perspectives. So depending on what you need to know, it’s a matter of everybody’s got slightly different information requirements. And also different levels of detail. What we’re also doing to navigate through all of this information what information is fixed and what’s likely to change. For example, for a cavity barrier there is information that is static because that’s come from the manufacturer, but there might be some specific information about that particular cavity barrier in that location. So, if we can differentiate between the two it would be good.

The other thing is that the safety case reports and the fire risk assessments, it’s great to know that you’ve got one, but it could be out of date the following day, so what we really need is a safety management system and a fire management system that is also live. So the report is an output that you need to track, but that in itself isn’t adequate as far as the building safety side of things is concerned, because when things change the risk assessments really should be rerun. It’s also the case that we find that we want to break out things like fire stopping inspections, for example, to be able to see what’s changed, if a problem’s been identified under a fire risk assessment, then works that have been carried out, has that actually been completed.

Importantly, finally it’s a matter of tying that inspection, for example, back to an individual asset record and not creating a new one, because we’ve discovered that when people are using applications often they’re creating a new record for a particular asset, and actually what they’re doing is they’re just creating the golden thread is just for the inspection, not for the asset, so we’re losing the track of the information. So, if we’ve got asset tags, for example, those are tied to a particular asset and we can then test the information to see if that particular asset has got the additional information that’s needed can then be tied back to manufacturers product data, but you also need to look at it in the context of where that door is. So, just looking at an inspection without understanding where it is and the spaces that it’s protecting isn’t really adequate.

And then if people are using applications like Plan Radar, Riskbase, Hilti, Keystone or Civica, to be able to identify the individual assets, it all needs to come back to the individual information. Because in part we’ve got so many golden threads now, the success of what we’ve been doing is good, but what we’re actually ending up with are the landlord is ending up having to deal with dozens or potentially hundreds of different golden threads, so we need to be able to bring together that information. Finally, the information on machine-readable information. Here we’ve got a data sheet where we’re showing fire rating and really to interpret the fire rating for this particular door, a human has to read that, or that, or that, you’ve got fire rating all described in different ways. So what we want to try and do, for example in this session here, is if there is a data sheet for a cavity barrier, what is the key information that we need to know about that cavity barrier and can we hold that as machine-readable information. Whereas, for example, the acoustic level, that might be just in a data sheet.

So the exercise of doing that, we’ve been on this journey for a couple of years now, and we’ve been working with HACT to create standardised data templates that can then be used either for existing buildings and new buildings, so that we can organise the information in a way that any software application can then read. This is the exercise that we went through with the BRE to create standardised data templates. The point about this is that then you’ve got a standard name for, for example, a balcony door. We’ve got a classification for it, we’ve also got the IFC classification which is the BIM standard, and but glueing these together it makes the job a lot easier to find things and keep them up to date.

Also, people use different terms, so it might be an Automatic Opening Vent is described in an asset management system as an AOV or a smoke vent or automatic air vent. We can do this in the database to be able to use different synonyms. So, overall we’ve identified 71 fire related assets and 152 that are safety related. Now that can change and depending on an interpretation, but at least we’re starting to get there. The other thing is about the asset data. Part of what we’re trying to do today is to understand what information is unique to cavity barriers that is different than it would be for a fire damper. This is standard COBie and this is generic for any type of asset, manufacturer, model number etc. The thing that makes it different is the information that you might have for different types of assets.

The most widely delivered at the moment is IFC data which is in the BIM world, but there’s also different information sets. CIBSE, for example, the Chartered Building Services Engineers, they’ve got a set of information that is needed and that’s what’s influenced FIREY (BS8644). You’ve also got cost information from RICS, you’ve got distribution, this is what wholesalers and builders merchants use, the ETIM classification. The point is when we’re looking for the right information it’s got to be for the right purpose. This is IFC for an Automatic Opening Vent and you’ll see a lot of these attributes here are probably only needed for design purposes. So my argument now is probably we have these just in a data sheet, but things like fire rating and height and width, that’s something that perhaps should be managed, going forward, as machine-readable data.

And if we do that it means it can be collected without having to put into BIM models, this can be generated in data templates or spreadsheets for contractors to find.

A big challenge that we’ve got is the only people that really know what you need for a cavity barrier are people that really understand both the manufacture, the installation and the maintenance and asset management of cavity barriers. So that’s the purpose of today and the big question that we’re trying to answer is what data do we need and in most cases we’re told ‘it depends’. In depends on what that cavity barrier is doing, what was its specification and what’s responsible for it. So, we’ve gone through this exercise now with AOVs on Monday, Fire Doors on Tuesday, we did smoke dampers yesterday, but what we’re doing is really reviewing the hard work that some of the people that are on this call put in 18 months ago.

We want to refresh that in the context of the Act and if we can do that it means that the information that we’re capturing can be used in any software application because we’re able to hold the data as a discrete auditable set of information that can then be connected to any software that’s got a door. And by doing that it means that we can add in the new BS8644 information, for example, into that same library and then populate any system so it makes it neutral and generic. So, that’s what we’re trying to achieve.

RICHARD Jiss, put the document up and then we can go through it. So this is the first question we want to look at: what risks do cavity barriers mitigate? Take a few minutes and have a flick through there and see if anything stands out as glaringly missing or wrong or needing more explanation.

GEORGE I’ve just realised that in the presentation I just gave there was a number of slides that I’d hidden. It would make this exercise a little easier for people to understand what we’re doing if I could just jump back into that. (shares screen). For the 12 asset types, we tried to identify to make it easier for people to understand, in this particular case a door, a lot of people don’t know the difference between a door and a door set and what the integral parts of that are. This is an example, and we’ve done a similar thing for cavity barriers, but also look at this through the context of what that particular asset is doing. So the purpose of this exercise is to really answer the information that the HSE and the regulators asked us to address. So it’s not a matter of looking at a cavity barrier in itself, it’s what is that cavity barrier doing, and largely probably forming part of a compartment and it’s there really to mitigate a risk or a hazard.

So, in this particular case we’ve got a fire breaking out in a kitchen and we’ve got a number of different measures, or treatments as the HSE call them, to protect against the spread of smoke. So therefore it’s really important, not just that the cavity barrier or the fire door is in place, but also the penetration seals. And therefore it’s a matter of understanding what data do we need about all of these items to ensure they perform when called on. But if they fail to perform then you’ve also got to look at the smoke control system and also the detection system. All of these individual assets are forming part of a system and in fact the systems are forming part of a complete measure. So, the exercise that Richard just started there was to look at things initially from a point of view of what’s it doing, why do we have that particular asset in place. Also, what do people do to it to stop it from working.

This is coming at it very much from the regulators point of view is what risk are we mitigating. Also, what information do we need to have to ensure that it performs as required. For example, the location, the spaces that that particular asset is protecting, and any component parts that are provided. So, again, these are the sorts of measures that we want to be talking about. So, this is the second question, what information is needed. The third question is what tasks are needed to ensure that it will perform as it needs to. So that might be for making sure the specification was right, the installation and also the inspection. The same with competency: what level of competency is needed to ensure that any work is carried out to the best effect. And then finally how should we manage change. So if, for example, a particular cavity barrier had been chosen and then somebody couldn’t get that particular one and it gets swapped out, how is that decision taken, how is that related back to the original performance specification, and how is that change recorded so that we end up with better information.

RICHARD what risks do cavity barriers mitigate? Anybody got any comments?

MARTIN MILNER Can we say hot smoke because some of the intumescence will allow some cold smoke through it past it. If we say risk of smoke buildup the smoke will pass an intumescent until the intumescent temperature reaches 120 degrees or so. So you’ve got quite a bit of smoke passing that which is one of the challenges that intumescent cavity barriers have in the housing market. While they’re universally accepted in curtain walling they’re not universally accepted in housing.

RICHARD Yeah, presumably you can still choke on ? 20mins 28secs, can’t you?

MARTIN MILNER You can, but within the context of the cavity that smoke is unlikely to get to you. I’m thinking that’s just on the first one, but cards on the table, it’s a way of recognising the difference between intumescence and full fill cavity barriers like a mineral wool sock.

RICHARD What I should have said at the beginning is that we record this session and e have an in-depth highpoint document that comes from this which includes everything that goes in the chat. Some of the things you’ll put in the chat will be directly related to a point, and Jiss will add that during the meeting, some of the things you’ll say in the chat will be adjacent but still of interest and we’ll put those in an appendix.

ADAM HEATH I just wanted to build on what Martin was saying. I guess there is a distinction between intumescent open state cavity barriers and then fully filled or closed system cavity barriers. With the intumescence sometimes in external wall cavities people might build in cold smoke detailing in addition to having the intumescent if cold smoke detailing is a requirement for the project, so it’s something that does occur on some sites but not all sites. But I think Martin’s point on maybe having a distinction between what kind of cavity barriers we’re discussing, because I think we’ve read through the document and there’s mentions of intumescent, but I think in other places there’s mentions of kind of closed sealed systems and they will operate slightly differently.

With the intumescence, as Martin said they’ve all got activation temperatures, but typically they need to close within 5 minutes of a test start time, but in the test it’s a furnace that’s ramping up the temperature quite quickly, so if it’s a slowly developing fire I guess you might have a little bit more cold smoke, but if it’s in an external cavity then, as Martin said, it might be less likely to interact with people within the building before it becomes more developed.

RICHARD We’ve not taken account of that in the past, this is new, I’ve not heard this before, so it’s very interesting. it just goes to show the amount of meetings and input e’ve had into this document someone will always find something new, and that’s why we’re doing this.

DAVID POAT I’m trying to think about this from an end user/client perspective in terms of the usefulness of this document and I’m kind of wondering whether this list of risks is too long. I’m not suggesting it’s not comprehensive or that the things that are identified here are inappropriate, but there are things on this list that don’t relate to fire safety. Degrading acoustics, yes, it’s a risk, but do we want this document to focus on fire safety, building safety only, or is the intent that it goes beyond that. I’m also wondering whether some of these risks could possibly be clustered together, just to make the document easier to read and digest. I’m thinking about people and how they might use this document in the future.

GEORGE The purpose of this, to some extent, is largely to capture the knowledge and experience of all these different subject matter experts, so it’s not expected to be used as it is as an end result. What I’m hoping to do is to be able to hold all of this information and then filter it out so that you have different views. So, it might be you, for example, in development or maybe your colleagues in compliance or repairs or whatever, they’d need very much a subset of this information. But if we can start by pulling together the things that the experts that are in here say is useful…

That was the point I was making earlier that a lot of what we’re doing here is around product selection and specification and you might think that specification information would be in MBS or something like that, but what’s become very clear is that the way specifications are currently put together they’re not adequately prescriptive to be able to provide, maybe in 5-10 years time, the alternative…A cavity barrier could be damaged if it gets wet and therefore if it needs replacing how do you find out what the original specification was that was caused to select it.

RICHARD Does that answer your question, David?

DAVID PEAT It’s certainly given this document more context for me, in terms of understanding what it’s trying to do, so that’s fine.

RICHARD Welcome to Chris, our in-house cavity barriers expert. Chris, we’re just going through question 1a, what risks do cavity barriers mitigate. We’ve had it highlighted the difference between intumescent cavity barriers and full fill, so we’ve got that on there. Is there anything you want to add to that?

OK, question 1b, this is about the risks to cavity barriers themselves. What risks are cavity barriers themselves susceptible to. We’ve got a general section at the top, then in terms of materials, installation and inspection. Have a click flick through those and see if anything is glaringly missing or needs adapting.

CHRIS HALL The first one, I think that’s a copy/paste from another event. I was just trying to think it would a hell of a cavity if there was a sofa in the way. I’d say the risk of human intervention, smoke detectors or stuff like that wouldn’t have any impact on cavity barriers> The thing with most cavity barriers is that they’re generally hidden from view. do we cover elsewhere the risk of cavity barriers in the wrong place?

RICHARD Yes, that should be under installation.

DAVID POAT A question for Chris: Do the cavity barriers form part of the cause and effect kind of process for building safety?

CHRIS HALL I guess they do, in a roundabout sort of way. It’s not a document that would be used on a regular basis or a kind of a process that one might use when selecting a cavity barrier, but I don’t see any reason in the context of what we’re trying to do here why at least in couldn’t be benchmarked against it and if need be removed later, but for now I’d be inclined to leave it in.

LAURA SMITH I don’t think many people in the industry would associate cavity barriers with your cause and effect, it’s generally around how your fire alarm interacts with all your third-party systems, so I wouldn’t think that one would be a risk of cavity barriers, it would be more linked to AOV systems, dampers, fire doors, rather than cavity barriers. It’s more for your active than the passive side.

CHRIS HALL I take your point, it’s not something that I would see regularly as a consideration.

DAVID POAT A couple of things, Richard. I think you’ve suggested Chris talked about water damage, I don’t see anything about water damage on this list.

GEORGE It’s under materials, it’s down in the next section.

CHRIS HALL On the subject of water damage, just to clear up any misconceptions. The products generally are OK if they get wet. In other words, if during construction they’re subject to what I’d call construction moisture and some of them are in damp cavities as a matter of course. We had a situation recently where a cavity barrier, somebody managed to do something silly in a 10th floor flat and released 120 litres of water into the cavity. That’s what I mean by water damage, not just moisture. What damaged the cavity barrier there? It was the water, but it was the pressure - it blew it all away, it swept all before it, as you would expect 120 litres of water would in a 50 mil cavity.

GEORGE Chris, if there was a leak that was running for months because nobody was able to figure out where it was coming from, there was a leak in a wall where there was a cavity barrier, presumably that would be a risk?

CHRIS HALL But minor, because most of them are made from mineral wall products and they generally have a water repellence capability, most of them have got foil facings on them. It tends to be significant amounts of water rather than….

RICHARD So it’s like a deluge, so it’s more about the pressure than it being water.

CHRIS HALL It is, and it’s as much to do with the wind on high-rise buildings as it is to do with the rain, if they’ve been left. If you can imagine your in the middle of Birmingham, you’ve got a 30-storey building, it’s been left exposed at the top. Normally they’re checked before they’re closed off anyway.

RICHARD So, is that where we’ve got building movement?

CHRIS HALL I’d put excessive water damage, physical/wind damage. I’d include it within materials.

NICK HAUGHTON Is there also one about other materials which in the space ?? 35mins 43secs…the barriers themselves degrading or whatever and creating gaps?

GEORGE I think that’s a really good point.


CHRIS HALL What would you have in mind, Nick? An example of such an incursion.


NICK HAUGHTON I wasn’t thinking of any particular product, but I was more thinking, for example,  I would have seen not very great interface details and so on. There is plenty if something is poorly constructed where it's interface or something and slipped 20 mil down or something, that could maybe be different streams first in there.


CHRIS HALL I’m thinking now down into the questions of installation and inspection. I think it’s a fair point, Nick, but I’m just at the moment trying to focus on the materials. Mechanical damage would obviously be a consideration. The bit about some laboratory testing not covering real life scenarios, the only way you can really test a cavity barrier, and I’m talking now about ones that are used in facades, is the unfortunate thing apart from BS8414 tests we really haven’t got anything significant that can be used to test in real life scenarios. Most of the products of cavity barriers are tested according to EN1366 part 4, and that’s a lab test for sure. Some laboratory tests are not covering real life scenarios, none of the laboratory testing really covers the in situ. If you wanted to go down that route, you’d have you'd have to do a large scale BS8414.


RICHARD So, we’ll delete the word ‘some’. OK, let’s move down to installation.


CHRIS HALL OK, we’re talking about now, this is a refurbishment and upgrade.


RICHARD Nick’s point would go in here.

CHRIS HALL Yeah. The ideal for most of these cavity barriers is they’re fix and forget, but if you go to refurbishment then you have to obviously make sure that you either replace them or they are inspected by the manufacturer or another competent authority to make sure they’re fit for purpose. In theory, most cavity barriers should be, general design life statements now going around for 60 years in masonry and other types of construction. But that point 5 covers that lack of appropriate remedial replacement of fire stopping or reinstating a cavity barrier after refurbishment. The only other thing that can happen in a refurbishment or an upgrade, if you’re changing the building use or changing the building layout then you might find that the cavity barrier technically might be in the wrong place. You might have to move them, or they might require realignment in accordance with the fire strategy.

I’ll give you an example. You have a building that was originally designated as an office block and all of a sudden it’s going to be turned into student accommodation or apartments. You have to look at that through a different lens. There’s a move now to almost stop buildings being demolished until it can be proven to a reasonable degree that they haven’t got a residual use and they can be repurposed, and that’s all part of the carbon agenda.

RICHARD Right so on here we’d put a 6V1, which is building change of use…

CHRIS HALL Requiring relocation of cavity barriers. You could also quote relocation and you might have to replace relocation and/or replacement.

RICHARD Well, presumably in this installation section there should be something along the lines of the competence of the installer, shouldn’t there?

CHRIS HALL There should. I can’t remember if there is anything else about inspection and installation, it should be installed by a competent person.

RICHARD Yeah, obviously we’ve got that for everything, so the installation stuff, I’ll put in in terms of competence. Then we’ve got…

CHRIS HALL I think that would be covered in a general, if most of them are inspected either by the manufacturer or the competent party, that’s a particular nuance of some types of cavity barriers where you have to basically lift the foil tape up to make sure that there’s not a hole behind it or that people aren’t covering a dog’s dinner with loads of…

RICHARD So, are you saying that’s not necessary?

CHRIS HALL I think it would be something that would be picked up normally in the inspection phase before you close the cavity off. Under normal circumstances, these days most cavity barriers, Tier 1 contractors are asking for a sign-off that this has been installed as it should be, and there’s an inspection process at that point.

RICHARD So should we delete the foil tape one?

CHRIS HALL I would replace it and put that the installation should have been inspected and confirmed as in accordance with manufacturers instructions. And that inspection process would pick up things like people using foil to cover a multitude of sins, wrong brackets in the wrong place, wrong fixings.

DAVID POAT Just a question on that Chris, I think the document goes on to talk about photographic evidence later on. What I’m wondering is whether that photographic evidence really needs to be taken before it gets covered with the foil, so that there’s that long ongoing record of the quality of the install.

CHRIS HALL This is a particular nuance and it’s born out of experience. The foil tape is necessary to seal often cavity barrier to cavity barrier joints. If you think you’ve got a horizontal joint there you cover it over. What you do find on occasion is you got to site and there’s miles and miles of tape, and experience tells us you don’t use miles and miles of tape unless you’re trying to hide something. You use a strip of tape. Sometimes when you see loads of tape you think is that there because…and they’re just trying to cover up their sins.

RICHARD It actually kind of covers what you’re saying in the inspection bit: foil tape obscuring missing evidence due to insufficient inspections. Kind of a backwards way of saying what you’re saying. Let’s go down to the next question which is what information is needed about cavity barriers to ensure they perform as required. We’re taking a slightly different view on this today that we took 18 months ago.

GEORGE (shares screen). What we’re trying to do is for each of the information sets that we are discussing we want to identify who needs that information and who’s responsible for producing it and who would then be accountable. RACI is the standard responsibility methodology. We’re not going to try and do this today, but one the things I wanted to alert you to is that a) we want to do this and secondly we want to identify what elements of that information could be in a manufacturers data sheets, all the information that’s provided in an O&M as a PDF document, but how much of it would need to be live. So, for example, I think a lot of that information would be relevant to that product wherever it’s being installed.

CHRIS HALL I’ll have a look through that, I’m not seeing anything in there that’s striking me as not being something that would be in…the only thing that I would say is that where it’s to do with the product most of the information would be contained within the manufacturers technical data sheet. I’m looking at line 7, as-built drawings, they wouldn’t be in the data, that would be elsewhere. The evidence the design is being copied out by a properly competent person, that wouldn’t be in the data sheet. The evidence the right product is being used shouldn’t be in the data sheet. Most of it would, though, but there’s certain elements. That to me, George, is almost like the golden thread requirements in an Excel spreadsheet, in a way.

GEORGE It is, absolutely. That’s what we’re really trying to interpret from this exercise, to see what information is project specific and therefore may need to be changed, and what information is generic that is coming from Siderise, for example.

CHRIS HALL Separately, myself or my colleague Adam that’s on this call, we could go through our data sheets and tell you what would be in out technical data sheets and what wouldn’t be.

RICHARD Let’s get onto question 2. Let’s see what sections we’ve got: requirements, specification, performance, materials, construction, installation, inspection, maintenance. What information, the type of cavity barrier, size, manufacturer, design life, as-built drawings, documentation. Anybody got anything to say on those?

GEORGE Could somebody tell us the different types of cavity barrier. How many different types are there?

CHRIS HALL Basically you’ve got…it’s not so much the types, it’s where they’re used. Generally you can find anywhere within a hidden cavity, so you can have a cavity barrier above a suspended ceiling…

GEORGE Sorry, what would help me, Chris, if we could talk about rather than where it’s being used, are there 3 or 4 fundamentally different types of cavity barrier?

CHRIS HALL OK. There are products that are intumescent based and they tend to be used in ventilated cavities. They can be intumescence on their own or can be amalgamations of intumescent with other suitable material. There are mineral wool cavity barriers that tend to be the most common, those you’d see used internally and externally within buildings. There are cavity barriers that I would say deal with extensive voids above suspended ceilings and they tend to be supported by wire mesh, so they can be hung effectively. There are intumescents as well where a piece of timber can be used as a cavity barrier, so it’s quite a broad spectrum. Open state or full filled, and those tend to be mineral wool based.

ADAM HEATH Even the mineral wool one’s though, you’ve got kind of more rigid boards or you’ve got I guess the polythene bags with wool stuffed in, so even within mineral wool you’ve got a couple of different types. There are some barriers which are made out of kind of perforated metal and they’re less common, perforated metal with intumescence. And then if see somebody put injector clad in there which is kind of remedial, generally, and that’s a different type of technology. So, quite a few different options out there on the market. I think mineral wool based is fairly common for larger buildings, but there’s all sorts…particularly around openings the alternate materials that Martin’s got, using timber or steel or calcium silicate or gypsum can constitute a cavity barrier around a window opening.

RICHARD Anything else in requirements that we need to comment on?

CHRIS HALL You’ve got the integrity rating in there, you haven’t got the insulation rating. Put integrity and insulation rating. That’s in performance.

MARTIN MILNER Where would be the requirement to identify the substrate to which the cavity barriers are to be fixed?

CHRIS HALL I think it’s down in the bottom, materials surrounding substrates. So that can be internal or external.

ADAM HEATH The only thing I’d add in performance, it’s kind of linked into Martin’s comment, is just filed of application. Because that encompasses a lot of different things like, for example, for cavity barriers it might be void widths, substrates.

RICHARD Installation, let’s have a look at that.

CHRIS HALL The competent persons is in there. Fine, it’s fairly comprehensive.

RICHARD Inspection, just two points we’ve got in there. And maintenance.

CHRIS HALL Well, if it’s to be inspected, how? That’s an interesting point. During the construction phase now the inspection is quite rigorous in my recent experience in as much as there is a contactual requirement of most projects that the cavity barriers, wherever they may be, are inspected prior to them being closed off, for want of a better word. Post-construction, some of them are very difficult, so for example if you have a masonry construction they only to get to them is either knock the wall out on the inside or take your bricks out on the outside, and no one wants to do that. There are other ways of doing it, you can use borescopes, the kind of microfibre and they can go into the cavity and you can see, you can them on your mobile phone now. They can be inspected. Inspection, how you can do it, but mostly the inspection now tends to be at the installation phase with the idea being once it’s installed, if it’s installed well, it should stay in place for the lifetime of the building.

RICHARD So, this is an update from last time, they’re much more rigorous in terms of inspection during construction, so we need to put something in on that. Put a little green note, Jiss, add inspection during construction.

CHRIS HALL Where there tends to be most risk of being damaged and/or misused and/or abused tends to be above suspended ceilings and above raised access floors, where people are running services through, doing all kinds of stuff. Changing office configurations, moving partitions, dividing rooms up into different areas. Those are the ones that probably…you can still get access to them.

RICHARD And those are the ones that would be inspected because you can.

CHRIS HALL Exactly right. But if you’re looking at the facade ones, and this is particularly pertinent, if you look at modular construction now, if you’ve got a 4 unit thing, once they’re in place on the assumption you need cavity barriers in modular construction, you’re never going to see them again.

There should be maintenance requirements and to some degree that would go down to the position of where they are, and with Adam and Martin’s point, what type of cavity barriers they are. Generally now people are looking for what I’d call design life 60 years plus.

GEORGE I’ve got a question on this that I need the experts to feedback on, and in particular also the people who are attending from landlords. We’ve got Livewest, NHG and Origin on and possibly more. One of the questions that I’ve got is whether you need to record this information as an asset or not. Somebody told me that some of the landlords are not interested in knowing where the fire stopping is and they’re not interested in recording that as an asset, a fire collar as an asset. I think it relates to cavity barriers as well. My view is that you do need to know where your cavity barriers are, even if you’re not doing maintenance on them you need to be able to inspect them. What would the view of the people be…what about any landlords? Do you want to know where the cavity barriers are?

PENCHO STUDENKOV Part of Regulation 38, part actually of our process, at the very beginning we actually sent a checklist to developers so they know what items to expect to be inspected as part of Regulation 38 because we need to understand the building, we need to be able to maintain the building. So, as part of that checklist the very first details is actually specification from the architects where the cavity barriers are located. We see detailed drawings of where exactly and what products should be fitted, and then during the construction we also inspect the installation as part of the process. We now know what the product actually goes in, we obtain the data sheet of specifications, the test data, all of that. Obviously with the cavity barriers we know that when cavity barriers are vented or not vented and there’s the complexity of that. We also need to know what is the competency of the installers, we need to see the installation certificates as well, if that’s provided, So, all of this is actually being taken into account and being integrated into our process. So yes, cavity barriers are actually a very important aspect.

RICHARD Well, presumably, Chris, from what you said about change of use that could then alter how the cavity barriers were configured, then you’d have to know where they are.

CHRIS HALL It could lead to a change of requirement in performance, you might have to upgrade from one EI performance to a higher one, or possibly even a lower one. Most modern buildings, I’m talking generally new build here, most contracts want to know, as Pencho has said it’s Regulation 38, golden thread - where are the cavity barriers, where are they situated, are they there, and you need a full inventory of what’s there, what the specification is and evidence that what they’ve specified is actually used and it’s been installed in accordance. But I don’t understand the definition of an asset, in terms of…

BEX GIBSON In terms of meeting the legislation and the Building Safety Act we would require all of that information for the higher risk buildings, where they are, what state they were in last time, that’s why we’re having these inspections done now because we can’t really rely on the construction info. So, completely, yeah.

RICHARD OK, let’s go down to the next question. Question 3: What tasks, methods, statements and procedures are required to ensure that a cavity barrier is installed, commissioned, inspected and maintained properly? So this is about actions. Any comments?

PENCHO STUDENKOV To appoint an independent contractor to actually inspect the work and as part of the…obviously when the buildings are high-rise buildings we need SS1s and I’ve seen recently quite good inspection reports coming out.

DAVID POAT I’ve got a question for some of the experts on the second paragraph of the specification piece, fire engineering assessments might be acceptable from a competent chartered fire engineer. We got into a situation on a project 6-9 months ago where one of our representatives was asked after the test data for the cavity barriers that were being installed. In their normal circumstance it’s fine, if you’ve got horizontal runs, vertical runs it was fine. Where we started to get into difficulty was where there were bespoke details that were developed around things like cladding brackets, and there was just a big discussion about whether those scenarios had been either adequately tested or had been adequately assessed in terms of whether those design details would work or not.

The manufacturer that we were dealing with had their own in-house fire engineers who’d done an engineering assessment and deemed it to be satisfactory. we got into quite a convoluted debate as to whether we kind of considered that to be a suitable independent assessment. My question is, is this a standard industry position or is it considered to be an acceptable engineered solution if it’s done my the manufacturer?

CHRIS HALL No. Generally it depends on, it will vary project, situation to situation, contract to contract, and it depends basically on the requirements or the particular evidential requirements the responsible person or the accountable person will accept. Some people will accept engineering judgements from manufacturers on the basis of they know their products, they’ve got all the test data, they’re best to assess them. Others will require a third-party assessment by a completely independent party and my colleague Adam has just put a thing up there…it will vary from project to project and normally people require an independent review.

DAVID POAT Yeah, we ended up falling to the mercy of the building control. If building control signed it off then there wasn’t a huge amount that we could do as the client.

RICHARD Installation and inspection. Is there anything else that needs to be done during installation and inspection other than what we’ve got down there?

CHRIS HALL It’s a point of practicality, a 100% photographic record is no mean feat. I’ve seen them and I’m thinking about storage and access to these, some of them running to hundreds and hundreds of individual reports. It’s quite the undertaking to inspect every single centimetre of cavity barrier installed is no mean feat. It’s desirable, but not always practical as well. I would put ‘where possible’ for the photograph evidence. Ensure that the system tests are representative of the building, that’s a big one as well. There are a limited number of system tests and the only way you’d test say, for example, a multi-storey high-rise cladded building would be BS8414 tests, and with all due respect to the clients on this call they don’t particularly want to fork out £25-30,000 for an individual test for that particular project, and the main contractor doesn’t want to pay for it either. So, desirable yeah, practical no.

RICHARD Which one are we talking about?

CHRIS HALL Inspection, ensure that system tests are representative of the building. The point I’m trying to make is that I’d slightly rephrase that: ensure that the tests provided as evidence are acceptable and have been accepted as being adequate for the purpose of the building. And that could be anything from some people will accept product data, other people want complete system tests.

ADAM HEATH I guess, Chris, the point it might have been making is if you’re using a system test as your method of compliance. So, if that’s your method of getting signed off you’re saying, yeah, this is why the system is safe, you need to make sure you’re adhering to that system.

CHRIS HALL Yes, I hadn’t thought of that, that’s great. So, maybe ensure that the tests provided are evidence representing the building if you are using a system test as evidence of compliance.

RICHARD Let’s move down onto question 4, competency. What level of competency training needs to be in place for installation?

GEORGE Chris, is there a similar sort of accreditation body for cavity barriers?

CHRIS HALL Not really, no. Most responsible manufacturers offer an installation training of some sort, installation guidance.

GEORGE Should we take that out? If there isn’t an accreditation scheme…

CHRIS HALL I’d like to look at that separately…

RICHARD Yeah, this competency piece is always a can of worms, would you mind doing that. Chris?

CHRIS HALL I don’t mind doing it at all, because there’s lots of discussions going on. The unfortunate thing is there’s a few snake oil salesmen out there, they’re saying we’ve got this competency…

RICHARD Yeah, and this is something that could have changed a lot over the last 18 months - 2 years.

CHRIS HALL It’s developed no end, sometimes for the better, sometimes for the worse.

NICK HAUGHTON There’s a lot of work being done on the external wall systems competency piece, there’s been a white paper headed up by the Institute of Construction Management and Waites Construction. Having been involved in that and knowing that, I think there is quite a lot going on about that.

CHRIS HALL There is, and also, for example, the Structural Timber Association have got a good system of installing cavity barriers in timber framed buildings, but that doesn’t confer competence in installing them in rain screen systems with metal things. The problem that we’ve seen is that people are going to a provider who said, oh, I’ve got a certificate to install cavity barriers, you go along, they’ve haven’t got a clue what they’re doing. They’ve had a couple of hours training on one particular system, they’ve now got a tick in a box and away you go. It’s wrong, that’s going to solve nothing.

NICK HAUGHTON The joint ? JCI? 1hr 19mins is looking at the broader picture of actually the end to end from sales people and their competency to technical advice and designers and everything. Personally I think it probably encapsulates this as well when it comes to install.

RICHARD OK, what I suggest we do, a lot of what we’ve got here is possibly out of date, some of it will still hold. Chris, if you don’t mind we can liaise with you on that to relook at that whole section.

CHRIS HALL I know that Gavin is involved as well in the JCI, and Martin Milner, the STA have done a lot of work…

RICHARD Well, let’s take this outside of this meeting and maybe have a meeting purely on that. So, we’ll park this one until we have the meeting outside in the next couple of weeks. Question 5 is how should product changes be recorded.

CHRIS HALL The product changes being recorded, that’s included in the Building Safety Act. If you change things, this is what you need to do.

GEORGE It’s certainly there as a requirement, what we’re saying is how do we go about doing it.

CHRIS HALL There’s a document being produced by CIOB and RIBA on managing safety critical elements. Within that document they have a fantastic section on dealing with changes.

GEORGE Great, and Adam’s put it in the chat.

CHRIS HALL It was fronted by the CEO of Mace and it’s got Paul McSoley’s recognisable stamp all over it.

RICHARD Has anyone got anything particular to add on change management or product change? OK, so as George said, if you’d like to put your name in the chat if you want to be involved in the competency piece, we’ll have a meeting on that.

GEORGE What we also want to do is, David was saying earlier, is to be able to group some of these information sets into something that is consumable. So, what we’ve done with the other groups is saying is if you’re interested in the data piece of how we can interpret this back into something that is usable from a data perspective, would you mind putting your name in the chat and ‘data’ against it and we can include you in that. The same with process, so if you’ve got a view of how this should be from a workflow perspective and who’s responsible for it, then do the same, but put ‘process’ in there. And the last one is application.

I hope you found this useful, we’re getting some fantastic engagement from the other groups as well, we’re pulling together some really rich information here that hopefully you’ll find useful, but also if we work collectively, because everybody on this is volunteering their time, is to turn this into something that is reusable. Could I finally ask, one of the things we want to get to is if we’re going to get the static or manufacturer’s specific information we’ve identified that data sheets themselves are generally there to sell the product to designers.

CHRIS HALL We’ve got product information sheets, we’ve got technical data sheets, they’re different things. A product information sheet is what you might call the pictorial representation, the technical data sheets are taking up the nuts and bolts and the real technical stuff.

GEORGE So, would you be able to share with us examples of that…are there any other manufacturers or suppliers of cavity barriers (other than Siderise) on the call?

CHRIS HALL Like all things in life you get the good, the bad and the indifferent. We’d like to think we’re at the top end in terms of providing data and in our business there is a clear distinction between a product information sheet and a technical data sheet, two different things.

GEORGE And which is which? If I want asset information.

CHRIS HALL The technical data sheet.

GEORGE OK, so the product information sheet is the marketing thing and the technical information sheet.



Martin Milner

re - risk of smoke  build up - to allow intumescent cavity barriers in external walls the risk of hot smoke

Dan Griffiths

Agree with Martin's comments. Intumescent cavity barriers are often used where air flow is required in normal operation, so cold smoke would move freely until the intumescent has activated at elevated temperatures.

Martin Milner

Risk of cavity barrier being damaged by materials falling down the cavity - a particularly external masonry walls where mortar falls and knocks the barrier off.

Adam Heath

Not on point 1a/1b specifically but there was a recent publication from CIOB and RIBA called "A guide to managing Safety-Critical Element in Building Construction"  which may be of use / interest. they use cavity barriers as a worked example.

Nick Haughton

another one for the previous list is that there is probably some clarity needed on what 'system failure is' ... i

Bex Gibson

Risk of change in required standards? e.g. materials installed 30 years ago may not be to today's standards....

Martin Milner

on low rise houses the absence or damaged of a cavity barrier over a window may allow fire spread into a cavity and by pass the cladding fire resistance.

Structural Timber Frame building movement can cause pressures on cavity barriers with an external wall cavity

need to know what the cavity barriers are to be installed against - eg masonry to masonry or render cladding to timber frame.

Design life - of the building, cladding  or cavity barrier?

what the cb has been tested against should be in the data sheet and then compare with the housing construction

Bex Gibson

e.g. injectaclad

Martin Milner

open state or closed full filled

full fill are - stone wool, steel plate formats, timber

we also have the ones that work and the ones that do not

Adam Heath

field of application for test results

inspection of follow on trades not disturbing cavity barriers - like cladding battens

Bex Gibson

It should be in the O&Ms? Depends on whether EWS1 form is required

Agreed with Pencho - we rely on reliable information from construction as baseline

However, we also carry out inspections if required for an EWS1

Adam Heath

FRAEW in accordance with PAS 9980  for existing buildings under scope of Fire Safety Act 2021

Martin Milner

an independent review on manufacture

Adam Heath

EJ's require to be completed in line with PFPF guidance

Martin Milner

can not often get access to inspect CB

David Poat

Yes thats what we found

Adam Heath

There are some schemes out there but they are unlikely to be manufacturer specific, more material agnostic

Martin Milner

The STA has a training programme and test for installers and looking to develop it for approval but it moves slowly