insulating plaster for solid walls

[Oldude (Dept 53)]

We have a small building with 50 cm thick walls. We want to insulate it without using batten and plasterboard as this will reduce the available space. Can any one help us find a supplier of insulating plaster/render that we can do ourselves (we believe it has polysterene balls in it). We are based in the Mayenne area. Many thanks.

[Nick Trollope]

I'm not aware of a product that will insulate, the only use I am aware of for poly balls is to make concrete lighter although adding polystyrene to render would increase it's insulation. However, inch for inch, the "R" value is bound to be lower than that of straight polystyrene.

Then again, 50cm stone walls should have a pretty god insulation value in their own right. Do you have another problem (such as damp) that you are trying to mask? Few of the properties around here, with walls of that thickness, are insulated although most of them are dry-lined (usually to exclude damp).

 

[Oldude (Dept 53)]

Thanks for the reply. We don't have a damp problem. I spent February camped in he property whilst I dug out the concrete and stone floor and boy was it cold. We are having under floor heating fitted. But I would like to avoid putting up metal studwork, insulating and plasterboarding as space is very tight and this could take away some of the floor space. Would normal sand and cement render and a skim coat be okay or do I need to find a product than will insulate within in the platster coat?

[zeb]

As they are solid stone walls you could always repoint them using a lime/sand mix or lime plaster them - old stones need to breathe so a cement render won't do them any good at all. Many houses have repointed interior walls and find that other insulation isn't necessary.

But, I'd make sure the roof is well insulated!