Dry - Wet Risers BIM4Housing Roundtables 04-07-2023

RICHARD …putting what we’re doing today in context, of what we’ve been doing in the past with BIM4Housing, past guidance and where we’re heading in the future. (All participants have previously heard George’s introduction). That being the case I suggest we skip the introduction and dive straight into it. What are the component elements of a dry or wet riser system? Have a quick flick through there and see if there is anything that stands out as missing or amendable. Are there people on the call who are actually involved directly with wet dry risers?

MO FISHER Yes, I am. with location and specification on drawings through the practice.

RICHARD Because there is a question that George wanted me to ask and that is, firstly, do dry and wet risers have pumps?

MO FISHER No, it’s just wet risers.

RICHARD Secondly, how important is it in terms of the available hose length? As in, if there was a fire on the 13th floor, potentially they might have to get water from the 10th floor and this sort of thing. How does that get managed?

MO FISHER My understanding is that’s where the regs come into play, so if you have your 50 metres etc that is your wet riser provision, once your above 50 metres. So anything up to 50 metres can be dry riser and then the pumping appliance is basically your fire brigade fire & rescue service pumping appliance. That’s the guidance we worked under ADB.

RICHARD Got it. Are there any dependencies for dry wet risers on other systems?

DAVID LESLIE Not dry risers. Wet risers need water supplies for their own pumps.

ADAM SANDERS Do you need to cover anything on falling mains, rather than just rising mains?

MO FISHER Never used a falling main, never seen one specified.

DAVID LESLIE I have used them. I’m an ex-operational fire officer, so I have used them, but they tend to be warehouse scenarios, underground carparks, things like that, not generally in a domestic setting. They look identical, the inlet is identical, it’s just the pipe goes down not up.

MO FISHER So it would run off either system, like the wet riser, dry riser, its’ just a pipe that goes down rather than vertically up the building.

RICHARD OK, let’s move down then. What risks does a dry or wet riser system mitigate?

DAVID LESLIE Realistically, they don’t…in the grand scheme of things they don’t do any of those, really. They’re just for transporting water, so if you didn’t have a dry riser in a building over 18 metres the fire brigade would just run a hose through the centre of the stairwell or up the side of the building. A dry riser is just speed of fire attack, the speed that the fire brigade can get into a flat and if you have to run hose up 10 storeys obviously you can imagine how time consuming, how energy consuming and how people-intensive that is. So they are just a 100mil pipe that runs either internally or externally that transports water from the ground floor to whatever floor you need it on. So it\s actually speed of attack which will then obviously hamper all of those, so what they really do is speed up the fire services.

RICHARD Yeah, Paul’s just actually put that into the chat.

ADAM SANDERS Should you not take out all of those earlier points because they're all really just risk of fire rather than something that…A riser is going to mitigate the risk of fire spread or reduce the fire spread. All of those early bullet points are just risks of fire, whereas the two that we've just added are things that the risers actually directly mitigate.

RICHARD Yeah, I’m gonna raise that offline, I couldn’t really make that judgement. OK, question 1b: To what risks and dry and wet risers themselves susceptible? What stops them functioning?

MO FISHER Potentially one to add. It’s got wrongly placed outlets or inlets, but what we come across quite often is that there isn't the firefighting appliance accessibility allowed for, so it's not actually directly linked to the dry wet riser itself. But there's no point in having one there if you can't get your firefighting appliance within.

PAUL BRAY I'm a little bit puzzled about the undersized drainage system for drain down valves. Like wet risers, if you're gonna drain down a wet riser, you're gonna have to turn off the water supply to the wet riser in the first place. And you will drain it down to a place using a hose outside, so you shouldn't flood the pump room cause that would be…But I can see it as a risk, but dry riser, the dry riser drained ? 11mins 55secs is in the inlet delivery, which is on the outside of the building until you can either connect it to a hose, very rarely that I would ever see that get done, or you just open up the drain valve and it will drain itself out, which is good practice after use because it stops reduces the risk of corrosion.

RICHARD So that’s a risk for wet risers but not dry risers, is that what we\re saying?

PAUL BRAY …you would drain down a wet riser, and if you drain down a wet riser you’d drain it down to a point which is outside the building. I just think it goes back to the point I said earlier about it being poorly installed. A dry riser inlet should be within a certain distance of the access point for the fire fighters. If you’ve installed it in a place where you can’t reach it, what’s the point of it in the first place? It goes back to the design stage, not necessarily when it’s in use stage.

RICHARD So, potentially it is a problem for wet risers, but not potentially a problem for dry risers,

PAUL BRAY It shouldn’t be, if it’s been installed…It shouldn’t be for dry risers, because the drainage valve for a dry riser is outside. The problem comes when after you’ve used it, how do you disconnect your hoses from the outlet when they’re full of water because that will allow water into the building. It’s not a problem for the actual dry riser itself.

RICHARD Yeah, this is about issues for the actual piece of kit, really. What information is needed about riser systems to ensure that they perform as required? So what information do we need to know?

DAVID LESLIE Has it been copied from sprinklers?

RICHARD Not that I’m aware of.

DAVID LESLIE I just noticed it said so the room does not flood. I only ever dealt with a couple of buildings that installed wet risers so I don’t have a great deal of experience with them.

RICHARD Question 3: What tasks are required to ensure dry or wet riser systems are installed, commissioned, inspected and maintained properly? Anything in terms of installation? Nothing. So basically what we\re saying is this is a very simple piece of kit. There’s not really a great deal of complex digging and delving to be done about it. is that our consensus?

PAUL BRAY The Fire Safety England regulations have introduced a requirement that they get a visual inspection every month now, if they’re in buildings over 18 metres. In addition to any requirements for the British standard, the Fire Safety England regulations apply to the inspection for dry risers and wet risers, actually any fife fighting equipment in buildings.

RICHARD So that would come into maintenance. OK, let’s have a look at commissioned. No comments. In inspection, there’s an example from SFG 20…Maintenance. Paul, Fire Safety England have mandated…

PAUL BRAY I’ll write it into the chat box.

RICHARD So did somebody say this was Fire Safety England, what we’re looking at now?

ADAM SANDERS The Fire Safety England regulations have just said that in buildings over 18 metres there needs to be a monthly visual inspection. It's kind of like a non-technical inspection of all fire fighting equipment and they specifically put risers in there, but it's not hugely clear exactly what should be checked, and I think there was a paragraph somewhere which details some visual inspections and I think that might be quite helpful to have in there.

RICHARD So what we’re looking at on the screen now from Fire Safety England?

ADAM SANDERS I don’t think that’s from Fire Safety England, I don’t know where that screenshot is from. That looks like some kind of a British standard, maybe.

RICHARD Let’s have a look at question 4, which is about competency and training. What level of competency and training needs to be in place? Nothing. OK, question 5. How are changes from one product to another recorded? We've got some generic stuff under that. So what changes would be made and how would they be recorded? If there was a new pump would that need to fulfil certain requirements? Would it need to presumably have the same sort of performance as what it was replacing.

ADAM SANDERS Pumps normally just have an amount of head and a volume, like a litres per minute, so I think you’d end up getting quite technical if you went into that stuff. And then pumps generally have starters and then you might have backup generators, so I think you’d end up going into an infinite level of detail if you looked at all that stuff.

RICHARD Well, if there are system dependencies then it’s relevant. We’ve got that at the top in terms of dependencies, but they’re not directly this asset. Anything we’ve got written there more than covers it. We’re using the same methodology for all of these asset types and obviously some are very much more complex that others and it’s very easy to over-egg the pudding on some and make it more complex that it needs to be, which could be the case in point with those bullet points earlier on in question 1 that certain people in this meeting seemed to think are totally superfluous. OK, so we’ve gone through the document very quickly. It’s a relatively straightforward asset type that we’re talking about.

MO FISHER I had a couple of comments that have sort of been mentioned during this chat anyway. Not linked to the questions, but if Jiss can go to the front of the document, it’s where it says ‘what is a dry and wet riser’. It notes that most buildings have a wet riser, that isn’t the case in my experience, most buildings will have a dry riser. It’s just wet risers will be for buildings typically over 50 metres or if there is any other special requirement.

RICHARD Right, so that sentence would read ‘most buildings have a dry riser or a…’ what? Not a wet standpipe is it?

MO FISHER no, you would just have to separate that out as a sentence on its own and then if it’s a wet riser, where a wet riser system is applicable, or something like that, the pipes are kept full of water. You’d then roll into the next paragraph. I think for me it was just a little bit confusing reading this document cause you've got a dry riser in bold and then you've got wet risers below, but within the dry riser paragraphs you're containing information about wet risers. So it’s whether or not you just wanted to shift that whole paragraph into the next bold point and then it reads along the subject matter. And then another one, dry risers where it notes dry risers are used when the water pressure of a building wouldn’t be enough for fire suppression.

Typically we just work to dry risers are required when the building is 18 metres or plus and that covers that. And also when you can’t get a fire fighting appliance within 45 metres of hose length distance which is often missed within design, I’m focused on the layout/architectural side of it, but reading this that isn’t apparent and that is something that gets missed that if you’re not within 45 metres. You could have a 2 or 3 storey block of flats, nowhere near the 18 metre mark, but because of the length of the block of flats, the hose length is more than 45 and that would need a dry riser.

RICHARD OK, we’ll pick up what you said, Mo, from the recording. I have to say we didn’t obviously write this, it will be one of the guys from the earlier meetings who’s written this for us because we wouldn’t have this level of expertise.

PAUL BRAY I’d like to reiterate, I think there’s a lot of important comments there. I missed the beginning of this meeting, I would definitely have raised issues over the wording, it needs to be really clear and probably less complex. The dry risers are only required in buildings over a certain height or if you can’t get within a certain distance (45 metres) of the hose to any part of a building. That’s a newer requirement so you wouldn’t necessarily install that, but I think it’s really important to get the wording right.

RICHARD Of course it is. Most of the descriptions of the assets are very short, this one seems to be very long for some reason.

PAUL BRAY The other thing that I find why we’re making it more confusing, there are some quite straightforward descriptions of what a dry riser is and where they’re required within the actual approved documents and some of the guidance, so you could just lift that. Because are we getting into specifying details? When we start specifying it we’ve got to be careful because there is always an exception. So it might be that you say refer to that the guidance.

RICHARD Yeah, we don’t want to get into that. This is supposed to be a very basic few lines saying what it is, not to get into a load of detail.

MO FISHER I’ve dropped some bits in the chat that links ADB for what I’d be using and also the last one on here which I think is quite important, BS999O provides guidance that the horizontal pipe run from your dry riser inlet to the stair outlet can't be more than 18 metres. And again that's one that gets missed loads. You'll find that there can be 20, 23, 24 metres and then it has to become a justification and I don’t think we should be going that route, we should be sticking to what it is.

PAUL BRAY The other thing to note is that in new buildings over 50 metres it’s a requirement to be a wet riser, but you may find older buildings applied a different standard, I think it was over 60 metres. So you may go to a building that is over 50 metres but under 60 metres that may not have a wet riser. There’s little exceptions and discrepancies.

MO FISHER There was also something in the text, just sticking to the language being used, mentioning a dry riser in relation to sprinkler provision and for me that was confusing again. I wouldn’t use the dry riser terminology for sprinkler provision, although it might be within a sprinkler system but for me it’s clear cut within the approved document and British standards that wet riser/dry riser are fire mains only.

RICHARD Yeah, to be honest, that whole section, I’m gonna condense down to this and make it very basic, so we’ll be taking a lot of this out. it goes into much more detail than is necessary.

PAUL BRAY It sounds like it was generated by AI, to be fair.

RICHARD No, it wasn’t, it was one of the guys from the meeting 18 months ago. These meetings have been very interesting because you get 6 or 7 people in a meeting who really know their stuff and you kind of think that you’re going to get to some sort of equilibrium on an issue. But no, so often there’s two or three who are very definite about their belief in one thing and maybe three or four in another group absolutely believing that they are correct as well. It just shows that things aren’t clear cut. OK, any comments or anything, anything at all you want to raise? Well, thank you very much for coming and helping us with this. Obviously there is an amount of work to be done on this one, a lot of that will be excising non-essential description. Once it’s done we’ll get that over to you all and then hopefully we’ll come to an agreement on the contents. Now after the roundtables normal service resumes, we’ll be focusing on the existing workstreams and working groups.

There’s one thing George wanted to raise. We’re setting up three 1 1/2 hour sessions: one on data, as in if you’re interested in the actual information; another on process, if you’re interested in the processing of that information; and another on application, the application of the data. So if anybody has got any interest in joining one or more of those three sessions, put your name in the chat and that will happen over the next month or so.

IAN SMITH If you could just log my interest in the process one, Richard.

RICHARD Absolutely.



Paul Bray

allow for rapid deployment of firefighting media

reduce physical exertion of firefighters

needs to be within 18m of vehicle access

Fisher, Mo

Firefighting appliance accessibility, external design, hard-standings, turning heads etc

Adam Sanders

It's the Fire Safety (England) Regulations

Paul Bray

Fire Safety (England) Regulations 2022 require that all firefighting equipment provided for firefighters in buildings over 18m or 7 storeys or more are subject to a monthly visual inspection

The guidance say the checks are visual or 'other' check but it is not the intention of the regulations to require the responsible person to engage specialists to undertake these checks,

Fisher, Mo

Most buildings have Dry Risers.

Only buildings that have wet riser are +50m.

required in buildings over 18m in height as part of fire fighting shaft provision

or where a pumping appliance has not been provided to within 45m of all points inside each flat measured along the route of the hose. Section 13: 13.2 a & b

BS 9990 provides guidance that the run of horizontal connecting pipe is a maximum of 18m in length.