Insulating old stone walled house

ianjames1

Hey,

Looking for a bit of advice. We are in the middle of a complete renovation project on a 100+++ year old house. We have completely stripped it down to nothing but the bare walls which are 2 foot thick stone/rubble and muck.

Trying to find the best way of insulating now. Our last house was around the same age - with similar walls and had been renovated in the 80's. It had practically no insulation. It was cold, damp and hard to heat.

We want to do it right this time and need to save on energy costs. external wall insulation has been the major confusion so far and we are fast approaching the time to start installing it.

We have narrowed our options down to three possibilities and would be very grateful if you could let us know what you think or have any other ideas.

1. Good ole Kingspan - battening out the walls and sticking kingspan to them. plastering over. Drilling a few air holes in various places on external wall to allow air flow behind insulation.

2. The Isover Optima system - had a architect recommend this. The product says that it is fully breathable etc. which sounds the right job for our old walls but if you check out the video below you will see that the insulation is pressed right up against the wall. I'm not sure how great an idea this would be on the old damp stone that we have. Also, cannot find much information about using this product for this type of wall. I understand that it is used a lot in Europe, maybe not so much in the UK or Ireland.
https://www.youtube.com/watch?v=rcqDunjPoJM

3. Sheeps wool - We were going to make up the battened walls on the floor, put a vapour control layer on the back side of the battens and then fix the battened walled panels into position - leaving a gap between them and the wall for airflow. Then pop 100mm sheeps wool insulation between battens - possibly another vapour layer - (possibly smaller counter battens to run electrics) then plaster board.

If anyone could give some advice on the situation that would be great.

Many thanks

MicktheMan

Have you considered external wall insulation (EWI)?

ianjames1

Thanks for your reply Mick.

EWI ruled out though because the walls need to breath apparently. Stone will be exposed on the outside, pointed with lime. + roof has been redone already with very little overhang. Thanks

fozz10

mineral wool ewi should be fine. very breathable. used with the k rend type scratch coat finish

corkgsxr

Id do a outside wrap. The walls will dry out and it'll be fine.

Or if not id kingspan it

ccsolar

Hi Ian
I did my 1930,s cottage 15 years ago by dry lining it
It had concrete walls so I decided to build a 3x2 timber frame inside the house on every external wall, we fitted each section with 50mm high density insulation and covered with foil back slabs.
We allowed for a 1" gap between insulation and wall.
It has worked fantastic for us, the house has a B3 rating which I'm not happy about and plan to get a re-BER done, hoping for a B rating as the assessor didn't take into account the 100mm insulation under the floors.
We light a stove last night for 2hrs and the house was hopping.
Your main priority should be insulation everywhere first.

Hope this helps
Cc

hfallada

OP call U Value in Dublin. They specialise in selling insulation to the trade, so they actually know their stuff. Dont focus on the BER( its BS). But focus on what can save you the most money and give you comfort. Try underfloor insulation if you are going to have cement floors. Make sure you get triple-glazed windows. They are quite cheap now.

Outkast_IRE

Honestly OP external insulation wins in your scenario every time , have a general browse of the breaking the mould articles here http://www.josephlittlearchitects.com/articles

them and plenty of others have proved pretty well that on solid walls with no cavity external will be the best place for your insulation

ccsolar

ianjames1 wrote: »

EWI ruled out though because the walls need to breath apparently. Stone will be exposed on the outside, pointed with lime. + roof has been redone already with very little overhang. Thanks

I think the homeowner wants the old stone from the house on display Outkast

Outkast_IRE

ccsolar wrote: »

[/B]I think the homeowner wants the old stone from the house on display Outkast

Apologies missed that subsequent comment

Pixie Chief

Don't know a lot about this stuff so being very careful! We have just begun renovating a house that is 160 years old. It was last renovated in the early 60's and the damage that has been done to the stone walls by the drylining/insulation and pouring of concrete floors is devastating in some areas. These old houses absolutely do need to breathe and any and all materials you use need to be breathable from what I understand. After some fairly exhaustive research, we have realised that the walls themselves should not really need insulation in the way that a concrete block wall would. Research and discussions are still ongoing and would appreciate any opinions on the conclusions that we have drawn. Our options at the moment are to replace timber windows and doors with new timber windows and doors to minimize drafts, insulate the loft floor with earth wool but not under the slates (you insulate any water fittings lavishly but seperately), take out any dry lining/concrete/plasterboard/plaster that is inappropriate and repair and plaster walls with k-lime, dig out concrete floors and damp proof/insulate them with expanded clay aggregate/vermiculite and put in limecrete finished floors. We are also heating by stoves/ranges at the 3 original heating points (which is working pretty well - let you know as the winter goes on!) because central heating apparently doesn't do the same job at all. I think that the idea is that you allow the entire structure to breathe but insulate using breathable materials that were not available when these houses were originally built. Incidentally, so far they have been correct - our walls are actually toasty warm, even to put your hand on them whereas the patches of concrete in the walls installed earlier is freezing to the touch. Don't know if any of this helps - all comments gratefully received!