Hi,
I was looking at a product called Sempatap which is a flexible dense latex liner that is pasted onto internal walls in 5mm or 10mm thicknesses. I was looking at this to improve insulation/condensation proofing in difficult areas. Its flexible so can be pasted to curved areas. That was why I was looking at it. I have recently come across a number of curved areas that span across rooms in roofs, and are otherwise inaccessible. Also alongside some narrow stairs. However, the only retail price I could find seemed to be very high. The U value isn’t that good (although I believe the product is good for sound deadening) it looks like the stuff yoga mats are made of.

I discovered that the thin 2mm thick paste on polystyrene is still available, 2 layers of that has the same insulation as the 5mm sempatap (not much I grant you – but everything helps).

Isn’t this polystyrene stuff a fire hazard? I didnt think these types were still available.
Are there any other very thin flexible materials that can be used?

Please don’t suggest rip it all out and start again, I can’t make the oldsters live in the garden till next Easter, even if they could afford the job

Thanks in advance

The problem with insulation is that in order to get any decent effect you will need a reasonable thickness typically more than 100mm. The product mentioned above is very expensive. In my opinion 2mm of polystyrene or even 5/10mm 0f foamy stuff is a waste of time and effort and as you asked yes it is dangerous in the event of a fire it gives off toxic fumes so in that sense it is a fire hazard.

You could consider a dehumidifier run when the rooms are not occupied and paying for background heat in the occupied bedrooms when they are?

Hi, thanks for the comments. Aerogel would be nice, i've been following that separate thread.

Cheap and thin is the remit. The main reason being that when my wife volenteers me to decorate other peoples rooms I try to sneak in some thermal improvement. Roughtly speaking a thin layer of an insulant to an otherwise un-insulated wall is going to give about a 10-12% improvement in the thermal resiatance R value. All helps. I felt sure the polysytryene stuff was a hazard, thats why I was surprised to see on the shelves of the DIY stores.

Cheers

Hi, Thanks I’d appreciate that – its cheep.

I’ve just received samples of the sempatap plus a price list from the main agent. It’s still quite pricey although much less than it’s being advertised in some of the web eco boutiques.

It’s quite dense and doesn’t feel as warm to touch as expected. Being dense it will be good acoustically. The outer surface is quite hard and would easily take paint or paper. It seems bendy enough to go round external corners in window reveals etc.

It is as I expected a bit like a yoga mat.

Cheers again