OT: Recent Tests on High Rise cladding

[Bob Minchin]

If we are to believe the media, every sample of cladding (or do they mean the insulation or the cladding in combination with the insulation spaced so as to create a chimney effect?) has failed an unspecified test.

To me this indicates either the test is not the same as the materials were required to meet at the time they were specified; ie the test is either more stringent or is being done in a way that tests the material as installed rather than in isolation Or the materials were not up to the specification required at the time of installation which is far far more serious and heads should roll.

So far I have failed to find details of these tests and just keep coming back to media headline grabbing "all panels have failed the tests"

Can anyone shed good scientific light on this?

Bob

[newshound]

I've wondered the same thing. It looks to me like they are only removing the outer cladding for testing, not trying to test the whole system (cladding plus insulation plus air gaps plus fire breaks).

Might it be that they have devised a new test, say applying a propane torch to a bottom edge or corner, and are finding that all the panels behave much the same way as the Grenfell ones?

I think that is the way that I would approach the job.

[Nightjar]

One of the people being interviewed about this last night was very careful to state that the panels have failed to meet the current building standards. He didn't amplify and the interviewer didn't follow up, but I would take that to mean that there could have been a change in the standards. If so, presumably the Councils are giving priority to those blocks that were clad before the change.

[Davey]

Me too. It seems inconceivable that everything used up until now has failed its tests that must have been conducted to enable it to be used in the first place, so I agree that the tests now being applied must be different and/or more stringent. But the lack of explanation when stating that all panels now fail testing is most confusing and unhelpful.

[tabbypurr]

Maybe masses of cheap insulation panels will come onto the market suitable for bungalows.

[Clive Arthur]

You can make your own using straw bound together with candle wax and a magnesium outer skin.

Cheers

[nomail]

This was just discussed on R4 - apparently the tests now are on the core material rather than simply heating the aluminium coating of the sandwich. When I was designing things for a rather large IT company all the plastics needed to meet the vertial burning test in UL94 - V0 I think - so it would be interesting to hear how these cladding tests compare.

[Andrew]

If its 6 inches thick, then perfect for solid ground floors under the slab, especially if it's a fraction of the new cost.

[Davey]

And it was also mentioned on the BBC 1 pm news, so there is a recognition around that it is unclear what is being compared with what. Hopefully we will be told soon.

[Bob Minchin]

Thanks for this helpful lead. info here

about 20 minutes in.

[PeterC]

You have a flare for invention!

[spuorgelgoog]

But it might not have to meet the A2 "limited combustibility" tests anyway.

National House Builders' Council (NHBC) issued guidance which states that you can use a variety of sub-A2 insulation boards with B-grade external cladding ... The NHBC says Celotex RS 5000, the insulation used at Grenfell Tower can be used with B-grade cladding ... We have also identified one type of insulation that, they say, can be used safely with B-grade cladding, which is actually grade C.

So what's the point of having building regulations, and is a NHBC certificate on a new home (particularly a new home in a tower block) worth the non-fire-retardent paper it's printed on?

Owain

[Dave Plowman (News)]

Newsnight attempted to explain it yesterday. Not much the wiser - except that NHBC didn't apply to council blocks. Seems the sort of firm that builds tower blocks makes up their own regs. Or something.

[jimzzr]

Indeed it does seem that there may be an emerging theme whereby US standard s, published "Underwriters Limited" in a litigation/insurance environment a re often better in terms of fire protection than BS/EN standards that are o ften drafted by committees with strong manufacturer influence/representatio n.

[tabbypurr]

rds, published "Underwriters Limited" in a litigation/insurance environment are often better in terms of fire protection than BS/EN standards that are often drafted by committees with strong manufacturer influence/representat ion.

the organisation that approves wirenuts, push-in socket connections, cardbo ard mains insulation etc.

NT

[Huge]

[25 lines snipped]

It's "Underwriters Laboratories", BTW.

[charles]

The only BSI committee on which I served was 1/3 manufacturers, 1/3 users and 1/3 neutral outsiders.

[Dave Plowman (News)]

All the more need to make the structure as fire resistant as possible, then?