Advice on Solid Stone Wall Insulation

justmyself

I am about to start a full refurb on a Solid Stone Wall Town House from around 1850's. Heating, Electrics, Plumbing, Insulation, New Windows, doors etc... the works.

All advice read around the web is I need to be careful insulating this type of house. As solid stone walls need to breath.

From what I understand, a typical incorrect insulation is using insulated plasterboard internally. With nowhere to go, moisture reaches its dew point on the impermeable material, creating damp patches on the wall.

I can't cover the outside because of aesthetics. Anyway, covering the outside with non-permeable render can prevent internal moisture from escaping, again creating internal damp.

So basically I need to be careful what materials I use to make sure the evaporation will keep dampness levels in the building fabric below the levels at which decay can start to develop. Basically creating a 'breathing building'.

My basic understanding is I can't use run of the mill cavity wall insulation? But surely with all the advances of late there must be a Insulated Plasterboard & process I could use?

Can anyone suggest what approach i should take?

Thank you so much for your advice & help. Truly gratefully appreciated.





Here's a photo of the walls. It's an old house in need of a full refub, but there's no damp. It's good & solid. It's has big thick stone walls: 50-60cm. Currently has no ventilation, i plan to drill vent holes in each room (or the fact that chimneys are in each room, would that suffice?).

Bonzo Delaney

My tuppence worth would be the Isover optima dry lining system for breathability
Something worth looking at

"Mick the man" will be along shortly
He'll put you right

justmyself

Great Bonzo... fingers crossed i hear from Mick the Man !
As the latest bit of advice i was given doesn't sound all that right. It is as follows :

You can insulate the inside with whatever you like.
You only need a Vapour Barrier if your method includes a cavity or air gaps.
The walls breathe outwards regardless, and that won't concern you or this work.

The Steps...
1) Remove the existing plaster to bring the wall back to the stone work
2) Allow efficient time for the walls to dry out : -/+ 1 week
3) Then use BATTENS to attach the Insulated Plasterboard onto the walls? As DOT & DAB more than likely will attract moisture leading to damp patches?


What do you guys think. Sounds a bit risky to me?
Thanks

MicktheMan

You called

justmyself wrote: »

As the latest bit of advice i was given doesn't sound all that right. It is as follows :

You can insulate the inside with whatever you like.
You only need a Vapour Barrier if your method includes a cavity or air gaps.
The walls breathe outwards regardless, and that won't concern you or this work.

The Steps...
1) Remove the existing plaster to bring the wall back to the stone work
2) Allow efficient time for the walls to dry out : -/+ 1 week
3) Then use BATTENS to attach the Insulated Plasterboard onto the walls? As DOT & DAB more than likely will attract moisture leading to damp patches?


What do you guys think. Sounds a bit risky to me?
Thanks

Terrible advice, but I think you already new that.:)
Moisture is you enemy in such an old building when attempting to "upgrade" to modern standards. For starters, I wouldn't be relying on internet chat rooms to come up with a specification but instead get the input from a relevant professional (building conservationist / experienced architect) after they have surveyed the building. You cannot decide on insulation, air tightness, ventilation, heating, dpm, dpc etc etc in isolation but rather you need to take a holistic view of the whole project.
Having said all that, Calsitherm Climate Boards might be a good solution for the walls.
And finally ... there are much better ways of ventilating than "hole in wall" vents