post Grenfwll insulation options

Many companies make polyisocyanurate (PIR) foam insulation boards - kingspan and cellotex are just some of the more recognised brands. Ecotherm, rubbermaid, and many others make similar products.

PIR is classed as "combustible"[1] in the sense that it can be made to burn. However it will not sustain a flame or or spread fire in most circumstances. So generally is considered "safe" in domestic situations.

Other insulating products also tend to be combustible in one way or another.

Our insulation was injected into the cavity.

Insulation choices are dominated by price.

A guy wrote an article, about insulating his living room in London with this stuff, but liberal usage of this could equal the purchase price of your house. Presumably that's why only the one room was done :-) (The nature of the Google search results today, articles like that won't appear here. Searching where you are, will return different results than I can get now. "Google versus Canada" squabble.)

You can point a torch at it. And the reason that works, is you're not necessarily hot enough to melt glass. Maybe such experiments should be done with natural gas ("Bunsen burner") rather than propane.

There seems to be more interest in Aerogel pellets than sheets, so Aerogel may be used as a component in other insulation products. Rather than appearing in pure sheet form. In sheet form, a 0.75" thick sheet is a convenient thickness for the manufacturer. Making a 3" thick Aerogel would be just about impossible (as a single monolithic sheet). Nothing stops a user from stacking four sheets, but still...

You can get small pieces (a square foot) of Aerogel sheet for science fair projects. That's how typical end users get to play with some.

Paul

Celotex is owned by Saint-Gobain who also own Jewson and a ton of other building brands (Gyproc, British Gypsum, Isover...). So you'll have to cut a fairly wide swathe to avoid them.

Because PIR is so bulky, there's not much point a merchant stocking multiple brands of what's an identical product to another brand - so you'll likely get whatever brand the merchant can get a good deal on.

If you really want to avoid them look at other materials, either mineral wool (avoiding Isover), sheep's wool or wood fibre.

Theo

I think this type of cladding is really only a problem in high rise flats. If you only have two or three stories it just flares up and fizzles out.

I haven't read the report, but AIUI there are two problems.

1. The cladding made the fire travel vertically up the building, spreading it to more floors. A normal concrete building would just have a fire burn out one flat and that would be it.
2. All oil-based materials (eg regular PIR foam) will burn if you get them hot enough. They may be 'fireproof' which just means they'll resist burning for long enough to get people out. Typically a 'half hour' rating is common for houses - enough for the fire brigade to turn up and go in to drag everyone out. That becomes more complicated in a high rise - more people, more floors, limited ways down. That's why choice of materials is more critical.

'Fireproof' materials often means that they won't propagate the start of a fire - ie throw a lighted match and the material will scorch but not catch fire. That prevents spread, but if you have fitted the building with flammable cladding then the fire has already taken hold and it's hot enough that the material will eventually catch fire, as it would do if you held it in a blue gas flame for long enough.

In all this discussion we're focused on getting the people out - there's no consideration that the building will be anything other than a write-off afterwards. But even if you use only mineral based materials that don't burn, timber elements may still do (eg roof trusses), and the amount of smoke and water damage (from fire hoses) may well mean it's a write off anyway.

So this is less of a problem for your shed, where you don't sleep and would get out at the first sign of fire. But it is understandable if you don't wish to support brands with such a cavalier attitude to fire safety.

Theo

None of which do the job as well and two of which are more inflammable.

AFAICR it was the combination of the cladding with the insulation that caused the problem

In the phase 2 report there is clear evidence that aluminium and polyethylene cladding burnt like petrol soaked rags when in a vertical position.

7.79 Aluminium composite panels with polyethylene cores were selected for testing because they represented a product that was available on the market and was of interest to the construction industry.When subjected to a full-scale test, a system incorporating panels of that kind reached the failure criteria in Fire Note 9 at a very early stage, exceeding the external temperature limits within three minutes of the start and the internal limits after 4.34 minutes. Staff intervened to terminate the test, manually extinguishing the crib fire at 5.45 minutes and ending the test at 5.75 minutes.

Detailed observations recorded during the test included the fact that at

7.80 Dr Colwell was present at the test and was shocked both by the rapid rate at which the fire grew and the extent of its growth. By contrast, Dr Smith did not recall the test as being particularly notable and did not remember anyone at BRE being particularly surprised at the way in which the system failed. She simply noted that the test had failed at an early stage.

7.82 In the light of the test it was clear to Dr Colwell and Dr Smith that ACM panels with unmodified polyethylene cores were not suitable for use in cladding systems on high-rise buildings. Nonetheless, in its report dated 16 September 2002 BRE said only that the aluminium sheet product had satisfied Class 0 but had proved to be one of the worst performing products in the intermediate scale and Single Burning Item tests. It concluded by saying that, as the current guidance in Approved Document B asked for Class 0 performance in Diagram 40, those matters might require further consideration. That was as far as the report went.

Now I am unsure what the fuss is about kingspan. And PIR foam. The problem was clearly with the polythene and aluminium cladding, and BRE reported the facts, but no one read anything into them enough to take any further action. BRE was not tasked with presenting an opinion, only the facts. The department of presumably health and safety was more concerned about 'harmonising' standards with the EU than assessing building material safety

I repeat, it wasnt the insulation that caught fire. It was the cladding

But it will burn (giving off horrid fumes) as long as you leave a flame playing on it, and the grenfell cladding formed tall chimneys which did exactly that ...

Yes.

PIR foam dies not burn. It is endothermic. At best after prolonged exposure to high temperatures it fumes a bit and loses structural integrity

I have held a blowtorch onto PIR foam for an hour and it f****ng does not burn.

At best it smokes a little and crumbles.

There is clear misdirection going on here trying to point the blame on celotex and kingspan insulation when as you correctly point out, it was the cladding that enabled the fire to spread. And provided the main source of fuel.

Yes. Exactly. Buildings have to withstand effectively a 45 minute fire standard. So that timber and steel etc is behind fireproof cladding. The twin towers failed almost to the minute after 45 minutes.

Fire safety is not about protecting the building, its about protecting the occupants by warning them in time to get out, and supplying a safe means for them to do so.,

Grenfell ironically was probably totally fire safe before its eco-cladding was applied.

No 100% it was the polythene cladding that caught fire

Without that there wouldnt have been any real fire at all.

We know *now* that it was the reynobond PE (rather than FR) that burnt, but my test was in the immediate aftermath of grenfell when it looked like the insulatin might be to blame, my test burnt more vigorously than that video, but did self-extinguish when not held in flame, I think Tim Watts did a similar test ... If I could get into the garage I'd repeat it.

I have some kingspan or celotex as loft insulation. I tested it with ablowlamp and was unable to make it burn. It charred but would not sustain a fire. The dodgy one is expanded polystyrene which is what was used in the cladding at grenfell.

Aerogel appears to be available quite readily, and was a favoured material in a retrofit course I did recently because it's breathable and insulates well. Incredibly expensive though.

Some of the alternatives cause their own problems such as insect infestation unless heavily dosed with insecticide which may have health concerns.

Does the Grenfell enquiry negate the usefulness or effectiveness of Kingspan type insulation in a typical domestic 2 storey house or for a shed? Surely the "risk" not only is the base materials but the way it is installed. Greefell was a chimney lined with flammable material and incorrectly installed material around windows. In a domestic house fire you are more likely to die from poisonous gasses from your burning furniture and the fire spread by the curtains catching light than from anything to do with the insulation.

Yes, but I wasn't worried about my shed burning - it's made of wood anyway. What I was concernred about was buying products from disreputabe companies who had profited from reckless practices and then refused to be reponsible.

TW

No, it wasnt. What was used in the cladding was polythene and aluminiun

Wiki...

"aluminium composite cladding panels, which included a 2 mm (0.079-inch) highly combustible polyethylene filler to bond each panel face together. As is typical in rainscreen cladding systems, a ventilated cavity between the insulation board and rear of the cladding panel existed"

Wiki also claims that PIR was and is inflammable. It isn't as you an I can testify

Kingspan is not flammable

It was the cladding that was inflammable.

All furniture and curtains have been illegal to sell unless fireproofed for years now.

I used Quinntherm. It seemed to be dimensionally more accurate than Celotex, especially when using 25mm boards, in other words absolutely flat, and no 'ripples'.