Superquilt insulation - has anyone used it?

[whiskyowl]

My builders are fitting this to the outside of the build, under cladding. Never come across it before, and slightly worried about how it performs in relation to Kingspan/Celotex. It looks like something you'd use on the Millennium Falcon. Can anyone shed light?

Inside there are a few inches of sprayfoam insulation, so this won't be the only insulation I have, but I was expecting foam boards. Apparently these are now £££ in price due to a shortage - worried whether I'm getting an inferior product here, or whether it's actually OK?!

this is the stuff that looks like kitchen foil, with a layer of bubble wrap inside?

I've hear it said that the claims for insulation are overstated. Presumably your house is being built to BRs and the architect has specified the thermal performance of the walls. Do you know what was in the plan that was submitted and approved?

That's the stuff, only it has multiple layers inside it, not just one. Am worried that you say it's no good!

Plan says:

"100mm cavity with full fill cavity board. Xtratherm Thin R-plus or similar approved- down to 30mm below floor insulation to top of wall. 100mm blockwork, plasterboard/wet plaster and skim. To achieve min u-value of 0.28 W/M2.

Horizontal cedar cladding - VTw 18f x 145f face. 50mm SW battens. Good quality vapour barrier. 50mm sheathing insulation - reciticel eurothane GP. 18mm external grade ply. 150x 50 SW studs at 600 cts partially filled with 90mm Recticel Eurothane GP. 11mm OSB with VCL over. Plasterboard and skim. To achieve min U-value of 0.16W/M2."

I have no idea which is the relevant bit, so typed it all out!

As far as I can tell, I have so far been given spray foam instead of the Thin-R plus and this superquilt instead of the recithel eurothane???

I have no idea how these compare, and no idea how to calculate the u-value.

have they included the 100mm thick insulation board (Celotex or similar) as specified in "100mm cavity with full fill cavity board?"

I would consider that the most important.

Xtratherm Thin R-plus is a rigid PIR board with a reflective coating.
www.xtratherm.com/products/thin-r-plus

Recticel Eurothane GP is a similar board.
www.recticelinsulation.co.uk/eurothane-gp/p4

It doesn't sound to me like they are building to specification.

Are you using a BCO from your local council, or an independent private company? I think you should phone your BCO and say that foil insulation is being used instead of the slab specified in the approved design, and you don't think it conforms to the approved plan. S/he should either come and look at it, or will speak to the builder on the phone, and will either be satisfied, or insist on the original plan being followed. Take photos of the build before it is covered up.

I believe the multifoil can be satisfactory, but it requires two or more layers with air gaps.

No - no insulation board. Open cell spray foam has been used instead, but to the same depth.

BCO are Aedis - I've rung and left a message. Will let you know what they say!

Just managed to get through! It's all fine - building control are happy that the u-values will be the same or lower.

I need a large glass of brandy.

What is going on with Kingspan/Celotex prices, though? There seems to be a national shortage!!

Oh, and where are my manners? In my relief, they have flown out the window. Thank you very much for your help @PigletJohn. As always you're a mine of information. I'm very grateful.

There a many ways of achieving the right amount of insulation - it's the u-value that is important and if Building control are happy with the build up that's ok even if it wasn't quite what you were expecting
I'm juggling u-values on a project at the moment and I can honestly say it's one of my least favourite bits of the job, but need to get it right to have a nice cosy house for my clients whilst also having the big expanses of glass they want.

wowfudge - You're so lovely, your clients are very lucky to have someone so conscientious in their corner.

Thanks for the reassurance, it's appreciated .

My house looks like something out of Star Trek right now!! All it needs is fins. It'll all be covered with cedar soon, but I'm quite enjoying the space age feel for now.

I believe there was a fire at the factory producing one of the ingredients for the foam, so all the European factories buying from it have had to cut production.

I was hoping to see Foamglas come down in price, it is made in IIRC Belgium and is so rarely used in the UK that you need to place an order for a lorryload for them to bother shipping it.

Being made of glass, it will not burn. After Grenfell I hoped it might become more common. It is usually dearer than the plastic foam.

PigletJohn- Oh how interesting. I've never heard of Foamglas. You're absolutely right, you would think there would be more interest in alternatives for large-scale public buildings. I fear that the horrors of Grenfell are fading all too fast from public consciousness. I only hope the multiple investigations that are ongoing will reignite a desire to get to the bottom of what went wrong there at every level.

Is there a national cladding shortage as well? I ask because some of the tower blocks in my city were stripped of their cladding after Grenfell and haven't been re-clad yet.

Glad you got it sorted, but a word of warning is my very experienced architect laughed when our builder asked if he could use it. The builder used celotex in the end. The claims they make for the foil are apparently exaggerated based on normal conditions, perhaps like the VW scandal?

I only know about the insulating foam shortage.

From what I hear, neither central government nor local government want to pay the price of new cladding.

I imagine anybody in the insulated-cladding trade, or anybody installing or specifying it, is going to be very very cautious.

AFAIK aluminium burns away almost like paper when it gets hot, and plastic foam will burn if it gets hot enough and gives off poisonous fumes. Even the fire retardant foam failed test no. 7.

I don't believe that stainless steel cladding burns, and I don't believe that fibreglass insulation or Foamglas burn. These are more expensive options, though. It is said that Kensington chiselled down the price of the cladding by £350,000 or so to reduce the quality below that originally specified by the architect.

IMO the Grenfell fire exposed disgraceful attitudes in central and local government, and those who have not yet been forced to resign are hoping to stay away from the blame.

However I am going off the subject.

Piglet - no, you're not off-topic, I asked you a question and you gave an insightful answer!

There do seem to have been some corners cut with the refurbs of these skyscrapers, in ways that don't really pay heed to the fact that someone living 20 stories up may require longer to get out of a building than someone with just 2 stories. It's appalling, really, that the old adage that "you get what you pay for" wasn't considered more carefully.

I wish I'd talked to you earlier about the insulation on my own build!!

Johnd2 - I wouldn't specify it myself (I've used a lot of natural insulate on most of my recent work mainly sheepswool but that comes with a premium price tag so you have to have a certain kind of client for that) but I have been in buildings that have it that have passed building inspections and seem to be performing correctly.

PigletJohn - Grenfell is going to have an impact on the industry but is suspect it's going to take longer than most people expect and will sadly be diluted by the influence of politics and money. Building regs are going to get an overhaul but a lot of the problems won't be solved by that alone and take a culture change which is much harder.
Steel insulated cladding was being very heavily pushed as an alternative at a recent CPD event I went to but I suspect the costs will have a real influence on how much it actually replaces aluminium.