France in Focus

It seems a balance between how much insulation to apply and how much space to lose.

Has anyone any useful links on what others have done in this?

TIA

I guess it wasn't so much as insulating against the cold, as damp-proofing, but similar conditions could apply! Our end room - the one half built into the hill, needed a false wall putting in, and a drainage system for any dampness that could seep through. It's not a big room, and we only lost maybe a foot wide of space on the longest side - we didn't put any insulation in, as it needed the air flow, but could you apply the same principle then fill it with the insulation of your choice?

I think it will be a case of compromise. Volume vs efficiency.
I am dry lining using a layer of the silver stuff on the old wall and 40mm slabs of expanded polystyrene between the metal uprights then 10mm plasterboard. I lose approx. 3" per wall. I'm not bothered about loss of volume in the room, just doing it the cheapest way with non itchy materials. Anyway, a smaller volume will cost less to heat.

Bayleaf wrote: ↑Thu Sep 29, 2022 11:02 amI guess it wasn't so much as insulating against the cold, as damp-proofing, but similar conditions could apply! Our end room - the one half built into the hill, needed a false wall putting in, and a drainage system for any dampness that could seep through. It's not a big room, and we only lost maybe a foot wide of space on the longest side - we didn't put any insulation in, as it needed the air flow, but could you apply the same principle then fill it with the insulation of your choice?

That raises an interesting second question - ventilation - do others put insulation directly against the stone or leave a gap?

Just a random thought, but have you considered insulating on the outside and then covering with crepi?

Ventilation?
Certainly if there is any damp or the possibility of damp - for example if the earth level outside is high compared to the floor level of the room.

exile wrote: ↑Thu Sep 29, 2022 11:13 amJust a random thought, but have you considered insulating on the outside and then covering with crepi?

Thanks - I discounted that as only some of the external wall will be insulated and the rest won't be.

niemeyjt wrote: ↑Thu Sep 29, 2022 11:12 am
That raises an interesting second question - ventilation - do others put insulation directly against the stone or leave a gap?

As our's is as exile suggests, half below ground, two holes were bored through the above-ground wall, and ventilation pipes/gauze put in. I would always be inclined to leave a small gap, whatever the reason.

Wasn't there advice against covering/sealing external old stone walls completely, as they "need to breath"?

niemeyjt wrote: ↑Thu Sep 29, 2022 11:12 am
That raises an interesting second question - ventilation - do others put insulation directly against the stone or leave a gap?

Having never done any renovations previously, we used our very old Readers Digest DIY for info and diagrams when putting up our placo. We cut square panels of placo and cemented them to the wall and then cemented the panels of placo to the squares. It also helped in that our walls were slightly angled inwards at the top so we could make all the walls appear as straight walls by adding a deeper square panel where necessary and it allowed a little gap for air to move around - not sure that what I've said makes any sense to anyone but me - but it did work