Internal wall insulation

[dames83]

Hi,

I've delved into the confusing subject of internal wall insulation.

I have a stone property, which I am planning to insulate the inside of the external walls. I would like to use breathable insulation and lime plaster.

I've considered hemp lime plaster, but worry that it won't be very insulative.

My thoughts are to go with the following, although I've not come across anyone using the same method:

25mm batten to stone wall
25mm Rockwool between battens
15mm wood wool board on battens
2x Lime plaster skim with render mesh embedded in the first coat.

Is this a reasonable solution?
Any thoughts/advice would be most appreciated.

 

[a twig]

There are a lot of threads already on here where people have looked at solutions like yours and the pros and cons vs other solutions, worth a search. Threads like:
Stone wall insulation

A

Thread 'Stone wall insulation advice'

Mar 3, 2021

Hi all, my first post on this forum . I recently managed to buy our first home which is an early 1900 stone house . It was all original with lathe and plaster ceilings and lime rendered walls, however the ceilings were sagging in a couple places after a previous water leak so we decided to pull them all down , then went onto remove all plaster off the walls and dug up the soil/stone floor . So we are back to a shell !

Floor insulation and under floor heating have been fitted , double glazed windows fitted throughout . Couple stud walls and roof insulation are being done this week ...

• A.jones
• Replies: 10
• Forum: Period Property Discussion Forum

Wood wool vs wood fibre

J

Thread 'Plastering question'

Oct 3, 2019

Hello all,

After nearly a year of serious unanticipated structural work we've now finished and can get on with fitting windows, plastering and everything else that we thought we'd be finished by now.

I have a question regarding use of wood wool boards on an external facing brick wall. This wall originally had laths fixed to battens that were fixed directly to the wall. Unfortunately, the internal plaster had to come down - partly because it was in terrible condition having been patched in various places with cement, gypsum plaster, plasterboard and any other poor intervention they could...

• jsmac
• Replies: 15
• Forum: Period Property Discussion Forum

 

[larry]

Rock wool is vapour permeable but not hygroscopic. It will not deal with the increased condensation risk you will create by lowering the temperature. Replace the rockwool with flexible wood fibre insulation and you will avoid that risk.

25mm isn't much and if you're limited for space you may be better with 40 or 50mm depth of rigid wood fibre insulation. The wood wool isn't as insulative. Wood fibre has a similar u value to rock wool.

I have done Flexi between battens and rigid and both are good solutions.

 

[dames83]

Thanks for the advice! I was thinking wood fiber could be a good alternative, and it's good to hear a positive recommendation for them.

I called into Ty Mawr Lime today and picked up some wood fiberboards. They were very helpful and offered lots of advice. I'm looking forward to getting the walls covered!

Thanks again

 

[Lacan07]

Thanks for the advice! I was thinking wood fiber could be a good alternative, and it's good to hear a positive recommendation for them.

I called into Ty Mawr Lime today and picked up some wood fiberboards. They were very helpful and offered lots of advice. I'm looking forward to getting the walls covered!

Thanks again

Good choice