internal breathable insulation for stone wall

st1979

Doing my own research into different ways to insulate the inside of stone wall. The wall is about 500 mm thick and is exposed on both inside and outside.
I want to improve the living conditions with out changing the outside. The wall pointing will be redone with lime on the outside.
What options do I have that won't cost too much. I can do most of the trades myself to keep costs down
Here is a few options I have looked at.
Hemp lime plaster the inside at 50mm
Hemp lime shuttered 100mm wall thn plaster for better insulated performance.
Calictherm.
Wood fibre boards
Granulated cork filled dry lining.
Sheep's wool behind dry lining.

Have looked at other options but some were obviously not breathable.
Like the hemp lime but only concern is would the lime breakdown the hemp. As lime is very corrosive.

Any other ideas.

Calahonda52

http://www.josephlittlearchitects.com/articles

lots on lime works.
Has wall/floor a dpc?
How smooth is the wall internally.
Calcitherm or wood fibre stuck on with the correct "glue", c/w ventilated service cavity
are my go to solutions for this

st1979

Calahonda52 wrote:

lots on lime works. Has wall/floor a dpc? How smooth is the wall internally. Calcitherm or wood fibre stuck on with the correct "glue", c/w ventilated service cavity are my go to solutions for this

Floor is going to be replaced. As it was raised a few times over the years for other reasons. So I can break it out. Was going to put dpc under the new concrete floor and use standard insulation. But put a thermal break between it and the wall. The walls have no dpc and would not be possible to install. The walls are pretty even but it is rough stone so will be up to 50mm to fill. Outside level will be dropped a bit and install a French drain around perimeter. I am not looking for a massive upgrade just something reasonable for comfort levels.
A few years ago my father would of just dry lined the walls like these and tbf some of those walls I have had the plasterboards off and they didn't look bad. But we have all moved on from those days

tabby aspreme

Have you looked at the lime mortar that contains cork.

BryanF

Research electro omosis

st1979

tabby aspreme wrote:

Have you looked at the lime mortar that contains cork.

Haven't found any info about it. But taught it might work. A friend of mine done a similar building in clay plaster as a place to stay when visiting family (summer time mostly). He just tried it out the other day and loves the 'feel' of it. But didn't do any insulation of the walls. Will have a look at it soon.

st1979

BryanF wrote:

Research electro omosis

Will do thanks

BryanF

st1979 wrote: »

Like the hemp lime but only concern is would the lime breakdown the hemp. As lime is very corrosive.

Wouldn’t be concerned about it. Again research hemplime, start with pier reviewed studies

st1979

Any taughts from anyone on open cell foam. Meant to be breathable. Another sales man was trying to tell me to put 50mm of closed cell foam direct to wall then open cell on top. Didn't seem right to me.

Calahonda52

st1979 wrote: »

Any taughts from anyone on open cell foam. Meant to be breathable. Another sales man was trying to tell me to put 50mm of closed cell foam direct to wall then open cell on top. Didn't seem right to me.

Foam has no capacity to handle actual moisture: the calcitherm/wood fibre products can, if required( and would be in this case) the ability to absorb and move large amounts of moisture.

Lumen

In theory, poured or sprayed closed cell foam works by keeping the dew point safely inside the insulation at a point which cannot be reached by relatively humid air inside the living areas.

In practice, there is a risk of gaps forming at the boundary between the foam and the walls, or at any service penetrations, which allows humid air to enter and reach the dew point where it will condense and be trapped, causing a mould risk.

So confidence in foam depends on the degree to which you believe the installers can achieve an absolutely perfect seal, and whether the product can somehow adhere to and move with the structure as it settles and moves with temperature changes over the life of the building, or your occupation of it.

RP123456789

Hi st1979, I created an account just to ask for an update on your project. I have a similar old stone wall house which I am looking to renovate in the next couple of years and was thinking about installing a french drain to deal with moisture issues and installing internal breathable insulation. How did your project go?

st1979

RP123456789 wrote: »

Hi st1979, I created an account just to ask for an update on your project. I have a similar old stone wall house which I am looking to renovate in the next couple of years and was thinking about installing a french drain to deal with moisture issues and installing internal breathable insulation. How did your project go?

Been very slow project. (my fault) I used a lime based insulation from natural lime company in tullow. Think its Cork or something mixed in it. It goes on like bonding then I put a clay based plaster from Clayworks in the UK on it. The clay is coloured to suit your finish. It's also breathable. Looks very nice. Just need to get the floors in and use the room. It's been sitting idle for last 8months. So haven't used the room apart from storage. But seems a lot warmer and no damp as of yet

RP123456789

st1979 wrote: »

Been very slow project. (my fault) I used a lime based insulation from natural lime company in tullow. Think its Cork or something mixed in it. It goes on like bonding then I put a clay based plaster from Clayworks in the UK on it. The clay is coloured to suit your finish. It's also breathable. Looks very nice. Just need to get the floors in and use the room. It's been sitting idle for last 8months. So haven't used the room apart from storage. But seems a lot warmer and no damp as of yet

Thanks for the update and best of luck with the rest of the project.

lynnedabell

in the same boat planning renovation of 1900s house, from all i have seen keeping the internal as original as possibel seems best way forward , external insulation that is installed well not to allow thermial bridging is maybe the option for me, what was name of company you got lime coat from ? like to see pics of clay finish if you have any
thks

Cathalp

Just created an account to find out about this type of thing. Almost at the internal insulation stage of my barn renovation. 80% sure I'm using hempcrete on the inside. Open to suggestions.

Calahonda52

whats the rest of the buildup from outside to inside?
do you have a dpc on floor and walls?
do you have MVHR?

Merrion

The ISOHemp blocks are quicker than cast-in-place hempcrete (we have done both and there is no significant difference in thermal performance between them)

Our building has no DPC but the breatheable (moisture permeable) nature of the hempcrete and lime plaster combination means this is not a problem.