What choices are there in fire resistant insulation?

at nearly twice the thickness ...

ructurally Insulated Panels, SIPS.

I'm sceptical of the security of this sort of material; it seems too easy t o cut through the wall with a jigsaw for burglarious purposes.

However for fire, in a single storey building with automatic fire detection and adequate exits, you should be able to get out quickly enough. The chap in the Grenfell flat where the fire started got out - it was the other peo ple in the building that were unfortunate.

Owain

The risks in low rise accommodation are different in the first place though, so its hard to make a call.

Just the presence of *any* insulation inside a closed space will result in faster fire spread, since it will facilitate a faster temperature rise in the room - you reach the point at which other combustible materials will spontaneously ignite sooner...

External insulation of a masonry structure (as per the tower) would probably be the best scenario for a domestic setting since the source of the fire is likely to be inside not the outside, and the higher thermal mass of the masonry will result in it taking a bit longer for a fire to start spreading rapidly as a result of auto ignition. (this may of course be a moot point since in most domestic situations the toxic smoke will get you before the fire does).

Hence the standard advice for domestic fires of detect it early, and if it can't be tackled easily and safely, the get out fast still seems like the best option.

Silica aerogel?

In message , at

Reinforced concrete, shirley?

I think its actually polyurethane and the flammable gas inside is somehow were not there in the stuff they use. its all a problem with how you set it on fire. if you heat outside or inside the heat tends to melt it first and it falls off, but if you delaminate it or get fire on its edge all bets are off, this as the guy on the bbc suggests is in fact what started the problem. Really that means that people have been basing safety on a false expectation of what fire will do. I really do think the regulators were asleep at the wheel to allow this crap to be seen as safety Fire will do whatever it wants, it does not always follow what you think it will do. Brian

Maybe we need to reevaluate asbestos cement. It may not be the most friendly of materials, and very heavy, but its a mineral and is only dangerous if fibrous or ground up into a fine powder. Of course its not very good for keeping you warm either, though it is good at not catching fire! Brian

I would count that as masonry for the purposes of this discussion.

You need something with a built-in fire suppressant, if such exists. For example, the kitchen work-top material 'Corian' contains aluminium hydroxide aka alumina trihydrate aka ATH aka Martifin aka gibbsite which acts both as an opacifier and as a fire suppressant. It decomposes at quite a low temperature by losing water as vapour/steam, thus sweeping away surrounding oxygen and inhibiting combustion. Magnesium hydroxide can perform a similar function.

But there are also a lot of organic additives to polymers that suppress combustion. For general information see

But I guess they all add expense...

Fire resistant celotex.

Usually you use either celotex or mineral walls in a cavity of somesort, but this is retrofitting to old shonk - blocks that should have never been put up, and should have died years ago

Glassfibre & rockwool batts/roll/loosefill.

NT

On 26-Jun-17 12:51 PM, Adam Aglionby wrote: ...

There are various foamed glass and foamed mineral panels that are inherently both fire and mould resistant.

In message , at

Only if you roll up your trouser leg.

But most doors can be cut through even easier or glass cut/removed, even roof tiles removed.

Yes, as long as you know about the fire and have suitable exits, it will take very little time to exit a normal house.

In the one case of a house fire that I was in (prior to homes having smoke alarms), the fire was detected, but ignored ... I was 9 and thought it was just the toaster buring the toast downstairs! I finished the chapter of the book I was reading, got out of bed and then found the fire. We cleared the house, called the fire brigade and waited. Fire damage was confined to my parents' bedroom (bed, furniture, carpet and one floorboard), smoke damage ruined everything upstairs, even the grout between the bathroom tiles!

With a smoke alarm, the fire would have been detected and acted upon early enough that we could have contained all the damage to the one room.

SteveW

Anything that isn`t steel or masonry is an attack vector for scroats.

FR PIR shouldn`t burn but apprently does

Aerogels look like a contender

Not cheap for sure

ticks the fire resistant box and lot thinner than mineral wool

Foamed glass dosent look cheap, energy intensive manufacture, but is available as cladding

Its a cost/risk balance but PIR unless it`s encased just dosent look like it`s worth the risk at any cost.

Mineral wool, asbestos and foamed concrete are about the only totally non flammable insulators.

Others depend on the gas in the bubbles and being isolated from the air.

TBH Harry suprised you didn`t suggest aerogels, nothing flammable and the bubbles are air, could even have left you some natural light through your windows ;-)

and of course the ones that *look* like they should work but do pretty much SFA

Why do you think they look like they should work? Basic physics says they are rubbish.

The only thing that gives really good insulation that is thin is a vacuum. Aerogels are quite good but nowhere near as good as a vacuum.