Solid wall insulation

[carolelloyd]

Can anyone advise on internal insulation for a double brick (Cheshire) solid wall in a house? I'm confused as to what to use. I've seen insulating plaster, wood boards, sheep wool ?? It's a cottage circa 1850

Thank you

 

[Glenn586]

I'm a big fan of wood fibre. I've installed 40mm on external walls in 2 different rooms and it's made a massive difference. I seem to remember reading at the time that just 20mm would half my heat loss.

 

[carolelloyd]

Thanks for that

 

[carolelloyd]

Could you tell me the one you used?

 

[lizziecupcakes]

I'm a big fan of wood fibre. I've installed 40mm on external walls in 2 different rooms and it's made a massive difference. I seem to remember reading at the time that just 20mm would half my heat loss.

Amazing!
How did you fix the wood fibre boards to the brick? I don’t get that bit

 

[DaveG]

Wall plugs and screws are manufacturers recommendations by the looks. I’m also interested in this.
I’ve had to take all the plaster off the bottom half of my walls due to concrete slurry and gypsum being there since maybe late 90s before our ownership.
I’ve hacked off everything back to stone on the bottom half of the wall and am thinking of just pointing/flattening the profile of the stones with lime pointing which leaves me a difference of about 40mm between the stone and the upper original lime plaster wall which I’ve left in tact.
I’m thinking if I put a 30mm wood fibre board along the bottom to make the majority of that depth up whether I can just make up the final 10mm with a lime finishing coat, blended in to the upper section?

 

[Glenn586]

Could you tell me the one you used?

Steico Therm glued to the wall with Isovit Lime. Make sure you get enough Isovit on the back of the insulation to fully bond to the wall with no air gaps. If your wall is really wobbly like mine you will need mechanical fixings to pull them into the undulations (an STR fixing pulled into a plug).

 

[Glenn586]

Wall plugs and screws are manufacturers recommendations by the looks. I’m also interested in this.
I’ve had to take all the plaster off the bottom half of my walls due to concrete slurry and gypsum being there since maybe late 90s before our ownership.
I’ve hacked off everything back to stone on the bottom half of the wall and am thinking of just pointing/flattening the profile of the stones with lime pointing which leaves me a difference of about 40mm between the stone and the upper original lime plaster wall which I’ve left in tact.
I’m thinking if I put a 30mm wood fibre board along the bottom to make the majority of that depth up whether I can just make up the final 10mm with a lime finishing coat, blended in to the upper section?

View attachment 15725

Rather than pointing I reckon you will be better and faster rendering the stone and gaps back to almost flat (let the trowel scrape over the points of the stones whilst you fill in all the nooks and crannies) and of course this does not have to look too pretty. This will give you be a much better surface to get a good contact between the insulation and wall. Get a weed sprayer and wet the wall down really well before doing this. 10mm is quite a build up of plaster, I think it's more realistic to be aiming for 5mm.

 

[a twig]

There are lots of threads on here about solid wall insulation - for example this thread covering both wood wool and wood fibre insulation options and installation methods

 

[Lacan07]

Can anyone advise on internal insulation for a double brick (Cheshire) solid wall in a house? I'm confused as to what to use. I've seen insulating plaster, wood boards, sheep wool ?? It's a cottage circa 1850

Thank you

Standard practice is wood fibre board - up to a maximum of 80mm thickness. This will give you the best bang for your buck temperature wise.

 

[aockenden]

Cork boards are another excellent option. Here’s my WFH outbuilding office at the moment. Ready to take a hemp-lime plaster base coat and a final traditional lime skim coat.

 

[Glenn586]

Cork boards are another excellent option. Here’s my WFH outbuilding office at the moment. Ready to take a hemp-lime plaster base coat and a final traditional lime skim coat.

View attachment 15728

Nice job. What thickness? Attached in the same way as wood fiber?

 

[aockenden]

Nice job. What thickness? Attached in the same way as wood fiber?

Thank you. 3 cm thick cork boards, NHL 3.5 + sand + fine hemp shiv bonding layer on the backside of the board at about 5-10 mm thick. Zero mechanical fixings, which I love!

 

[Lacan07]

Thank you. 3 cm thick cork boards, NHL 3.5 + sand + fine hemp shiv bonding layer on the backside of the board at about 5-10 mm thick. Zero mechanical fixings, which I love!

No fixings definitely a bonus

 

[Zebra]

External wall insulation is always going to be more effective than internal because it then keeps your walls themselves warmer. Also the risk with internal wall insulation is interstitial condensation: there forms a dew point within the wall itself causing the wall to become wetter and therefore colder than it would otherwise have been.