I mentioned this the other day in an insulation thread and an implication was made by someone that it was perhaps a dangerous topic….

Does anyone have any experience with this? I am thinking of putting it in the attic in my new house as the people I have spoken to about it have highly recommended it.

What’s the STW verdict?

I wouldn’t use it, I remain to be convinced that it offers equivalent thermal performance to more traditional insulation materials.

Yeah fair enough. I’m going off the opinions of my friend who has used it in his campervan, and my dad who is an architect/surveyor and would only give me an honest opinion, (obviously opinion is not fact) and they have both worked with it and found it surprisingly good compared with traditional materials. Tis pretty cheap too by comparison. 75m2 for under £100.

Why would you use this and not regular loft insulation? For radiant barriers to work properly they should be installed with an air gap in front of the ‘warm’ surface. That would be very hard to do in a loft. It doesn’t work on it’s own – it has to be part of a designed installation that gives the stand off.

Another problem with radiant barriers is the surface degrading.

Perhaps the people who sell it highly recommend it.

Oh – what insulation does your new house have in it now and how much? Easier to top that up than rip it out if it isn’t sufficient.

What aP said.
We installed it in attic of terrace house as a conversion. It needed a *lot* of faff to get right, and acres of tape to make it as airtight as possible.
It did work, it was warmish.
But, having done another house in fluffy insulation between woodwork, overlaid with sheets of rigid board, I can say it was not that warm really. Plus there was no noise insulation… Which was really noticeable. After three years, it also got drafty as the tape gave up…

Fair enough, sounds like it isn’t the most ideal thing then. The place I am getting has about 20mm of standard insulation. My surveyor recommended a minimum of 30mm so perhaps I just need to top up what’s already there.

The more insulation you can get down in the loft without compromising air flow around the eaves the better. I believe it’s still by far the cheapest way of saving money on heating bills. We’ve got at least 80mm down.

I tried to use the silver foil stuff in a garage once. It was rubbish compared with Celotex-type insulation and normal fibreglass roll insulation.

We put it up as in our loft you can see the tiles and its got to be better than nothing.
Was thinking of putting that thick stuff that they use when converting lofts.

We’ve got at least 80mm down.

That’s bugger all, think we’ve got about 200mm and that’s less than they recommend…

double bubble works well in the van – reduces road noise and keeps the heat in a bit longer but thats down to space constraints – if i could id have 50mm celotex in there – but then the van would be lots smaller.

i also have double bubble under the floor in the hall and the living room for similar reasons – dont have the height to put in celotex or ill be ducking for doors- the tiles in the hall are 2 degrees warmer than the ones in the bathroom right next to it so it does something.

but glasswood or celotex over double bubble EVERY time where its possible.

What’s the insulating properties of boxes and boxes of junk?

Double bubble – toil and trouble?

Would have been a better title 😀

quick hijack on a similar topic.

i live in a 1.5 story house – it was built that way in 1950 its not a conversion.

i have no insulation between my plasterboard and roof boards other than the airgap.

when i laboured for a builder doing loft conversions we always stuck celotex in this gap – but my understanding is everything needs to breath…..

retrofit celotex to this gap(maybe half the thickness of the gap leaving air flow or leave it fully open. I have 2 sheets of 50mm in the garage i need to use up. I would overboard on the outside with drylining but ill loose too much headheight.

answered my own question. long as i have a 50mm ventalated gap we are good – its 100mm at the moment so 50mm of insulation will help alot.

some thermal bridging at the rafters but cant do owt about that

What’s the insulating properties of boxes and boxes of junk?

🙂 I often wonder about that! Our loft is all well insulated apart from the middle where all the junk lives, which only has the depth of the rafters. How quickly does heat escape through boxes of Christmas decorations, old CDs, boxes of electrical appliances, suitcases…?