Jeremy Harris

Yes there was, and I believe it caused a change in the regulations there regarding fire stops to reduce the chance of vertical spread within the wall. I have also wondered whether it was a defrosting fridge problem. One of the residents that was interviewed said that the cause of the fire was a fridge in a flat on the same floor as his flat, having been told that by the occupant. Apparently the fire spread out of the open window near the fridge and perhaps that was what caused the EWI cladding to ignite. It sounds plausible, especially give the safety warning that's been put out about that make of fridge freezer.

Spot on. We built a flat area outside the back door, at the top of the gentle ramp up from the drive, big enough for a wheelchair to easily do a 360 on if need be, and I have a feeling that this was also buried in part M somewhere. We did it as I have a friend who's a wheelchair user, and also because my father was a wheelchair user for many years, so I was a bit more aware of the problems than some, perhaps. As a secondary point, the same gentle sloping path make it a lot easier to get wheelie bins out and back, too.

Something like wood fibre or cellulose, clad with OSB on the outside, and then clad with timber on battens, is reasonably fire resistant from the outside. Most domestic fires start inside, though, and the fire protection inside is provided by the combination of plasterboard and the internal board on the frame that protects the insulation layer. The main thing that limits internal fires is often the availability of oxygen. There are often small room fires that just burn out, without setting the house on fire, because they use up all the available oxygen in the room. Certainly a timber frame will burn, but it takes time for fire to gain hold, and the regs, and safety requirements, are really targeted at limiting the spread of fire for a certain time, long enough to get the occupants out is probably all that's needed.

Yes, dead easy. There is a DHW mode that can be activated by a dry contact between the 12V common and the DHW connection. The diagram I drew up a while ago, and posted here shows the connections:

Two pipes, a flow and return. The flow delivers water (inhibited, with antifreeze) at the programmed temperature, the return takes the cooler water back. It can be considered to be a low temperature boiler, and wired and plumbed in much the same way inside the house. Electrically, all it needs to run is power plus a dry contact programmer/thermostat, much the same as any other heating system. To programme it the Command Unit is needed, as that allow loads of settings to be changed.

The issue seems to be mainly one of preventing, or limiting, oxygen getting to any potential fire in the insulation. The reason that materials like wood fibre and cellulose have a poor Euroclass is because the test assumes that oxygen will be readily available. The blowtorch test is flawed, as the area around the blowtorch flame has very little free oxygen, much of it is consumed from the air immediately around the flame in order to keep the fuel burning. It's an impressive-looking test in a video, though. The blowtorch test does quickly set fire to flammable foam, because that melts around the immediate area of the blowtorch flame and then burns freely further away, where there is a greater amount of oxygen available. The conventional wisdom, with all sorts of flammable building materials, is that if they are encased within a fire resistant barrier material then they are usually far more fire resistant than just the material in open air. This is a principle that has been around for a long time, and predates the use of EWI. Initially, EWI was treated much like any other flammable building material, and just a layer of non-flammable material over it was considered adequate when it comes to making it sufficiently fire resistant. After several facade fires, this approach was revised, and new regulations covering the use of better fire barriers, especially around edges and above openings in the EWI. One problem seems to be that there are still inadequate provisions for preventing the vertical spread of fire within EWI, possibly because there is a bit of a conflict between the need to provide fire spread protection and the need to minimise thermal bridging through the insulation, I'm guessing. Because the main problem with EWI seems to be the chimney effect that occurs on tall buildings, which feeds large volumes of air into the bottom of the fire, I'm pretty sure that domestic scale (2 to 3 storey) EWI is reasonably safe, as long as there are good fire barriers above all the openings, so no escape routes are compromised. The priority with fire protection in the home has to be an effective alarm system, combined with a fast and accessible escape route. Saving the structure is very much a secondary concern, once the occupants have escaped safely. When it comes to sprinklers, then I believe they would have helped, particularly if they had been mist systems. When I was looking at fitting a sprinkler system, one of the points I noted about the fine mist systems was that they aided smoke suppression, as well as fire suppression. The very fine water droplets tend to wash out larger smoke particles, improving visibility a little. There are reports from eye witnesses that the firefighters were struggling to get access to the dry riser in this building. If this building is like many 1970's tower blocks, then the dry riser may well be connected directly to sprinklers. There are reports than the fire alarms failed to activate in some parts of the building, and there seems to be no evidence that the sprinkler systems were activated. All the photos of people who had left the building seemed to show they were dry, and there are no mentions that I've read of the sprinklers having activated.

What I find astounding is that facade fires exactly like this have been happening all around the world, on tall buildings fitted with EWI, for many years. They've been openly discussed on building-related forums for many years (witness the 5 year old AECB thread that @PeterStarck linked to). There are many YouTube videos of facade fires, other than the one I linked to. There are just as many fire resistance test videos around showing how fire can easily spread inside EWI on tall buildings. Despite all the evidence, no one seems to have done a damned thing to try and prevent fires like this. Why does it take a major UK fire, that has probably killed and injured many people, to get building regulations updated and enforced?

The problem is that the spread of fire elements of building regs are not as good as they should be when it comes to external wall insulation. The concern has been focussed on "surface spread" for years, and there has been a general acceptance that covering a flammable material with a non-flammable layer, capable of withstanding a given amount of heat for a given time, is OK. This doesn't really apply well to EWI, where a fire can spread very rapidly behind the external sheathing, with air being fed from below. There is work that has been done by BRE and others, regarding the provision of fire stops around openings etc, but sadly there seems to be a growing amount of evidence, from other fires, that these are not as effective as they should be.

Bad news indeed for Knauf, as the links to their news story on this refurbishment are all over the place, leading many, including me, to conclude that Knauf supplied the insulation. I'll edit the references to Knauf out of earlier posts, and suggest others do the same.

Both PIR and PUR can burn, depending on the exact make up. Here's a test of PIR: Generally, fire resistant PIR performs better than this, as far as I can tell from a quick look around, but it seems clear that fire resistance can vary a lot, within the same generic product description.

Structurally, I suspect that there would have been problems with using something like wood fibre or mineral fibre as the insulation, because that would add a fair bit of mass to the outside of the building, and may well have been just too heavy for the existing structure to take. I'm guessing here, but think that the choice of a lightweight exterior sheathing, aluminium it seems in this case, may also have been because of a need to keep the cladding mass down. Edited, in light of new information to remove an innocent companies name.

Edited, in light of new information to remove an innocent companies name. When I looked at this some time ago (around the time of that AECB link that @PeterStarck gave) I found a fair bit of evidence on fire testing that had been undertaken, by the German authorities and by the BRE. The testing was aimed at assessing the effectiveness of fire stops, particularly over openings, as some of the facade fires had allowed dripping, burning material to pour down as a sort of curtain of flame over openings. The temperatures can get very high in a cladding fire, they work a bit like chimney fires, in that air flows in at breaches in the fire stop layers lower down and gets funnelled up between the exterior sheathing (aluminium in this case, I think) and the original outside wall of the building. The photos of the early stages of the fire show this, with what look to be very high temperatures on the outside of the building, yet with the inside of the building still relatively unaffected by the fire, but almost certainly filling rapidly with smoke from outside (several witness accounts seem to support this). All the photos show the facade of the building burning very fiercely, above the ignition point on the fourth floor, with the fire spreading around the outside of the building. I would hazard a guess that the fire safety advice, to stay indoors, because the flats had a 90 minute fire resistance, may well have been outdated, and perhaps did not take into account the new external wall insulation. Clearly there was a significant external fire ingress risk through the windows and balconies, and I wonder whether that had been allowed for when the tenants were advised to stay indoors? I'm sure this will all be thoroughly investigated, but it wouldn't surprise me at all to find that the risk of fire entering a flat though a outside opening hadn't been examined since the building was clad.

Edited, in light of new information to remove an innocent companies name (article quote removed). There are other articles that state that the insulation was covered with aluminium architectural cladding, which I would guess was also intended to be a fire barrier. If the insulation was foam (and I think this is extremely likely - the mass would need to be low, because it's going on a 24 storey building) then it would have been treated with fire retardant, but no fire retardant will work on flammable foam if it gets exposed to high temperatures, the retardant can only really reduce the chance of the foam igniting accidentally.

Whilst I'd agree about the bias in that blog, it does seem a little prescient that the author of it wrote this sentence: Edited, in light of new information to remove an innocent companies name. I don't think it needs a detailed analysis to prove, beyond any reasonable doubt, there there are significant spread-of-fire risks from fitting flammable external wall insulation to high rise buildings; there have been enough cases of facade fires to prove this. The photos that have been published show pretty clearly that the spread of the fire was up the outside of the building, not the inside. Fires that spread from inside tend to show on the outside with smoke and flames coming out of windows; this fire shows the flames spreading over the outside walls. To balance this risk, and put it into perspective with regard to domestic properties, I don't believe that EPS/XPS EWI is really a problem with houses up to two or three storeys high. All the evidence available seems to show that facade fires like this almost always occur on tall buildings, where the intense heat can penetrate through parts of the structure and any fire breaks within the insulation itself. From the photos of Grenfell Tower, it seems that the aluminium cladding outside the insulation was actually burning as well, which gives an indication of the sort of temperatures generated around the outside of the building. Sadly, there are also eye witness reports that the firefighters were unable to access the dry riser - if they turn out to be true then it would have made things a lot worse, as they would have found it very hard to try and fight the fire from inside, I'd guess.

There are eyewitness reports that there was an appliance fire in a fourth floor flat, that may have been the cause: http://www.bbc.co.uk/news/av/uk-england-london-40270332/an-eyewitness-inside-the-tower-block-describes-the-scene-inside He reports the fire starting in a kitchen, spreading out the kitchen window and then igniting the flammable wall cladding. This photo (from the BBC News site) shows the early stages of the fire, spreading up from the window on the fourth floor where it started:

I believe that both @Monty Gerhardy and @craig have a commercial interest in supplying windows, so perhaps, in the interest of being fair to both businesses, that question should be addressed to both? Personally, I'm opposed to anyone using this forum as a way of getting free, thinly disguised, advertising.................

I remember looking into this a few years ago, when it was being discussed either on Ebuild or maybe the GBF, and concluding that there were some pretty dodgy assumptions being made about the fire risk. There were some changes made to the design of EWI, following tests that the BRE performed, that were intended to delay the propagation rate of fire in cladding and provide protection over openings, to reduce the risk of dripping, burning, plastic preventing the use of entrances/exits. As this building was only clad about a year ago, I would have hoped that it should be to the current standards. It seems very clear from the photos and reports that the spread of fire was very rapid, it went from the fourth floor to the top floor in a matter of a few minutes. I strongly suspect that the very dense smoke from the burning EWI may have been a significant cause of people being unable to escape. The building seems to have had only a single internal lift/stair well, and there are reports that this filled with dense smoke in the early stages of the fire. Edited to add: Sadly it seems that there have been fire concerns about this building for some time: https://grenfellactiongroup.wordpress.com/2016/11/20/kctmo-playing-with-fire/ Quote from that blog, from November 2016:

I understand that it was clad with EPS EWI a year or so ago. Looking at the photos it seems as if the vertical spread of fire was up the outside, most probably the EWI burning. The major problem with cladding high rise building in this way is that it creates a spread of fire risk vertically up all the walls, and what's worse, it prevents people leaving easily, or firefighters gaining entry, as the molten, burning, EPS drips down all around the walls. A search of YouTube for "facade fires" will show some nasty ones, like this:

Bigger is better, and the longer the air path the better, but other than that, make them any shape you like. One of ours ended up being a sort of trapezium shape, to fit in the space available, with the ducts offset from each other, the other is a rectangular box, sat on top of the fresh air feed plenum, with the ducts at right angles to each other. Both seem to work about the same, as far as I can tell with a Mk1, slightly ageing, ear.

I agree, we used five different not-VAT registered people. In our case there was no saving for the main build, because it was a new build and would have been zero rated anyway, but I've since used one of them for two landscaping jobs since we completed and the saving of 20% on the labour cost is definitely worth having.

@Ferdinand, that's a good question, as there don't seem to be any well-defined regulations or laws, just guidance and mention of competence. Like many, I expect, I used a scaffolding company, and they effectively certify the scaffold, in that it is there responsibility for ensuring that it is erected safely and is fit for purpose. They don't actually hand out any certificates, though, it's just a case that they are deemed to be competent and have the necessary insurance. We did have one company ask whether the scaffold we were supplying for them to use was certified, and they were satisfied by a verbal reassurance and being given the name of the scaffolding company. I would guess that they recorded this as a part of their own risk assessment process. I have no idea what they would have done if I'd said that I'd erected the scaffold, they may have been OK if told it was Kwikstage, for example (ours wasn't), or they may have baulked at using it. All told around 6 different companies/tradespeople used our scaffolding, plus me. The majority were pretty laid back about certification, with some just modifying the scaffolding themselves, something that caused me to get the scaffolders out twice to put right. I think that if you used a self-erected scaffold, then you would have to take responsibility for its safety, and that would almost certainly mean getting better insurance, as I doubt a standard self-build policy would cover it. Whether any insurer would provide cover for a self-erected scaffold I'm not sure, but they might well be OK with a recognised self-assembly system like Kwikstage. It's probably a bit of a grey area, though. I think my main concern would be liability, and the fact that people on site will re-arrange the scaffolding the moment that your back is turned. Never under-estimate the ability of people to be very stupid.......... In terms of risk, then I have a feeling that traditionally accident involving scaffolding have been amongst the most frequent types of accident on building sites.

I have ours (in the old house) wired to a PIR switch in the ceiling, so the mirror heater comes on for ten minutes whenever anyone goes into the bathroom. The PIR re-triggers if anyone is in there longer than ten minutes, keeping the heater on. This seems to work well, and is a lot better than the way we had it wired before, which was to the light (they are OK on lighting circuits, as they are only a few tens of watts). When it was on the light circuit we found that there were a lot of times in summer when we didn't turn the bathroom light on, so the mirror didn't demist. Now it works well all year around.

You can sand strand woven solid bamboo OK, as I've made some bits and pieces from offcuts. I'm pretty sure that only the lacquer would get scratched, anyway, and so a light rub down and re-finish would probably do the job. The lacquer is tough and a satin finish and seems to impregnate the whole boards, as it's also on the underside, too. I think that just waxing light scratches would be enough to make them invisible. I doubt that getting the stuff up would be any harder than getting up tiles or a stone floor, and might be a little easier. The Sikabond is certainly tough, but can be pulled away from concrete fairly cleanly, albeit with a lot of effort.

For some reason, the title of this thread reminded me of these old Spitting Image sketches:

Not so sure about doing the "dog experiment"! The surface of the bamboo is lacquered, and so about as scratch-resistant as timber. I'm sure the lacquer could be touched up if it got scratched, and I doubt that any dog claw scratch would touch the underlying bamboo, as it's really hard. We have solid, strand woven, bamboo, and on the ground floor it's bonded with Sikabond 95 directly to the concrete slab, which has UFH. In practice, the UFH never gets as hot as an area of floor in front of the French windows, that easily gets 50% hotter on sunny days that the UFH. Upstairs I bonded the bamboo directly to the OSB flooring. I think our bamboo boards are 140mm wide, T&G, and were dead easy to lay, as they are very accurately sized. The time consuming bit was spreading the Sikabond. Not sure about the engineered bamboo, but I'd say it's just not needed. Strand woven solid bamboo doesn't move like timber, and once bonded down it's not going anywhere.