Insulating stone house walls

[simon-0116]

Perfectly smooth just the same as ordinary plasters you have a base course and a finish coat with slightly different mixes. I am lazy and use ready mixed plasters in tubs that just need stirring with an electric drill stirrer to remix. Results even for me as a non plasterer are excellent and idiot proof. As for lime mortar the secret is in the brew of tea. You have to do an initial mix of the standard amounts of lime course sand and water with a drill mixer then put the kettle on for a brew then after half an hour of having your brew give the lime mortar a final mix before using.
Also with any sort of lime mortar or plaster I use a garden sprayer to apply water to whatever your doing as it acts like superglue.
Learnt the basic lime mortar and plaster methods on a practical 2 day course at Ty Mawr in Wales and was worth every penny and saved me a fortune. Would recommend to anyone with an old house.

Hi thanks for that. What did / would you use to fill deep holes / first coat straight on to stone. Was originally going to use sand cement , and now probably add lime to mix.
Is there any thing in a bag ready to use such as modern bonding coat.
Thanks

 

[spin cycle]

why cover up lovely old stone walls....strip back.....wire brush and seal.....or....use cement render

 

[renewablejohn]

Hi thanks for that. What did / would you use to fill deep holes / first coat straight on to stone. Was originally going to use sand cement , and now probably add lime to mix.
Is there any thing in a bag ready to use such as modern bonding coat.
Thanks

First coat filling in holes is normal lime mortar but spray water on the wall first as it acts like glue. then layers of coarse lime plaster (if your good with lime mortar you will only need one coat) then finally a layer of fine lime plaster.

 

[simon-0116]

Perfectly smooth just the same as ordinary plasters you have a base course and a finish coat with slightly different mixes. I am lazy and use ready mixed plasters in tubs that just need stirring with an electric drill stirrer to remix. Results even for me as a non plasterer are excellent and idiot proof. As for lime mortar the secret is in the brew of tea. You have to do an initial mix of the standard amounts of lime course sand and water with a drill mixer then put the kettle on for a brew then after half an hour of having your brew give the lime mortar a final mix before using.
Also with any sort of lime mortar or plaster I use a garden sprayer to apply water to whatever your doing as it acts like superglue.
Learnt the basic lime mortar and plaster methods on a practical 2 day course at Ty Mawr in Wales and was worth every penny and saved me a fortune. Would recommend to anyone with an old house.

What make of plaster did you use.
Priced up lime green solo plaster in bags, just add water and mix.

What mix is a starting point for lime render.
4:1
Thanks

 

[renewablejohn]

What make of plaster did you use.
Priced up lime green solo plaster in bags, just add water and mix.

What mix is a starting point for lime render.
4:1
Thanks

I used womersley in Dewsbury. Really recommend there products and there so knowledgeable and helpful. I use the ready mixed up tubs that womersley provide and they do a range of natural additives like hair or cork.

 

[Doogham]

https://bauwer.co.uk
I've just stripped a mix of lime plaster and modern plaster off a spare bedroom wall and replaced it with the bauwer light, because the room was not used much and has a north and west facing external wall it was always cold so we kept the door shut. Then when it was used the warm air condensed on the cold walls, the lime plaster bits were ok but the gypsum plaster bits were always spotted with mould and the paper was loose. Not finished it yet and I was going to post some pics when I have, the room is now noticeably warmer, the walls are not cold to the touch. I'm now regretting not doing the internal lath and plaster wall as the warm external wall shows up how much colder the internal wall is, I think because it is open to the attic and in spite of lots of insulation up there there is a cold draft circulating.

HI Stroller,

how did you get on the with the Bauwer and how has it been since you applied it? What thickness did you use ?,

Cheers,
Doogie

 

[stroller]

Hello
It was easy enough to use, the base coat was about 30mm thick, putting that on is a bit like vertical concreting, put some formers in, use a bit of plaster to hold them in place then throw the undercoat against the wall then screed it upwards to get the right thickness.
This was the first plastering I had ever done so I made a bit of a mess with the top coat and had to get a friend to show me the correct technique, but easy enough once I knew how.
The room is now warm and damp free, I borrowed a thermal camera, the wall viewed from outside showed up 1.5degree C colder than the rest of the house, inside it was a warmer colour than the other walls in the house, it was also an even temperature, the other walls had cold spots all over, probably where big stones are laid crossways and are creating a cold bridge. When I can afford it I will do other walls, its not cheap but probably similar cost to other methods, I'm just a tight git!

 

[Bonniehaha]

If the house has been empty for a certain amount of time theres a possibility of paying a reduced percentage of vat on the build / restoration. A friend of mine started his house renovation a month too early and lost out to the tune of £20k. Only found out about the scheme half way through the build.

That's really interesting! Do you have any details? We are about to embark on a restoration of a stone cottage which has been empty for a couple of years and on a tight budget, any savings would be amazing as we are doing the work ourselves. Would be grateful for any info. Thanks

 

[Timbo]

Started doing up a house to live in ourselves which is 2ft thick stone no damp coarse, very little damp only up to top skirt boards. Central heating in every room, loft insulation and double glazing.

So initial thoughts
Up stairs dot dab insulation plaster boards straight onto outside walls. Then plaster all walls with normal plaster.

Down stairs same but it's lime plastered so just wondered if it will effect it breathing as only a 10mm gap on dabs.

Also anyone had problems 5+ years if used normal plaster on stone . Plaster not keen on lime, presume because used to normal type.
Original plaster is all good just odd bits loose.
Dint want to regrets not using lime in 5 years plus.
Hope that all makes sense.
Thanks.

3 coats of Blackjack, last one with sharp sand thrown on, then bonding, then plasterboard dabbed, or plaster. You'll stop the walls breathing if you do it any other way.

 

[Secret Agronomist]

Getting a cottage done here, old plaster is being left on and they are putting a timber frame in with 100mm of rockwool type stuff (it's not rockwool exactly, a much denser sort of stuff but I can't remember the name). Then the ceilings are getting dropped as they are 270 at the moment. Again just a frame under the old ceiling, as you said it makes it nice and square. So on the outside walls we will have 25mm plasterboard, 100mm insulation, then original lath and plaster and then thick stone walls. I'm not 100% sure why they didnt take it right back to stone but the original lath and plaster only amounted to maybe 20mm. The celling will now have 25mm plasterboard, 100mm insulation, then the original joists with rockwool on top of that, also getting a new chipboard floor with insulation under it as well as it is a suspended floor. I also don't know why they used the wool stuff and not kingspan type , maybe for breathability?
There is an extension going on as well and it is getting 150mm kingspan basically all round it.

 

[Secret Agronomist]

That's really interesting! Do you have any details? We are about to embark on a restoration of a stone cottage which has been empty for a couple of years and on a tight budget, any savings would be amazing as we are doing the work ourselves. Would be grateful for any info. Thanks

If it's empty over 2 years you pay 5% not 20% vat. Get a letter from your empty homes officer at the council.

 

[renewablejohn]

Getting a cottage done here, old plaster is being left on and they are putting a timber frame in with 100mm of rockwool type stuff (it's not rockwool exactly, a much denser sort of stuff but I can't remember the name). Then the ceilings are getting dropped as they are 270 at the moment. Again just a frame under the old ceiling, as you said it makes it nice and square. So on the outside walls we will have 25mm plasterboard, 100mm insulation, then original lath and plaster and then thick stone walls. I'm not 100% sure why they didnt take it right back to stone but the original lath and plaster only amounted to maybe 20mm. The celling will now have 25mm plasterboard, 100mm insulation, then the original joists with rockwool on top of that, also getting a new chipboard floor with insulation under it as well as it is a suspended floor. I also don't know why they used the wool stuff and not kingspan type , maybe for breathability?
There is an extension going on as well and it is getting 150mm kingspan basically all round it.

Sounds like your creating a wonderful rodent home.

 

[Secret Agronomist]

Sounds like your creating a wonderful rodent home.

Wouldn't really matter what you did there would be some sort of cavity, unless you just left it as it is! Seems to be the way it get's done "here". Had 3 different tenders and they were all the same sort of process for the old cottage.
I suppose in theory we should strip it all back to stone and then you would still need a timber frame of some sort to square the room up and hold the insulation. I dare say they could have gone for kingspan but there would still be a gap between wall and insulation surely?
I did actually suggest knocking it down and building a completely new house It might not have had the charm but it would then have all been built the same!

 

[renewablejohn]

Wouldn't really matter what you did there would be some sort of cavity, unless you just left it as it is! Seems to be the way it get's done "here". Had 3 different tenders and they were all the same sort of process for the old cottage.
I suppose in theory we should strip it all back to stone and then you would still need a timber frame of some sort to square the room up and hold the insulation. I dare say they could have gone for kingspan but there would still be a gap between wall and insulation surely?
I did actually suggest knocking it down and building a completely new house It might not have had the charm but it would then have all been built the same!

Certainly not the way I would renovate an old stone cottage just sounds like a complete lack of understanding of how thick stone houses work.

 

[Secret Agronomist]

Certainly not the way I would renovate an old stone cottage just sounds like a complete lack of understanding of how thick stone houses work.

What would you suggest then?
It's too late anyway!
New windows and doors going in as well which will prevent draughts and new flooring, and I suppose you could argue that would have been enough along with extra loft insulation and it would have saved the internal insulation. The ceilings were really high for a cottage so we are bringing them down to a reasonable height (2.5 IIRC) which will also help with heating. There doesn't appear to be any damp in it all, it's on a very dry site anyway and after they lifted the floorboards everything under there was ok.

 

[renewablejohn]

What would you suggest then?
It's too late anyway!
New windows and doors going in as well which will prevent draughts and new flooring, and I suppose you could argue that would have been enough along with extra loft insulation and it would have saved the internal insulation. The ceilings were really high for a cottage so we are bringing them down to a reasonable height (2.5 IIRC) which will also help with heating. There doesn't appear to be any damp in it all, it's on a very dry site anyway and after they lifted the floorboards everything under there was ok.

Insulated solid floor using foamed glass and incorporating UFH (Both wet and electric to keep future options open) Make sure walls are sound lime mortar and breathing then replaster with lime mortar with final layers incorporating cork. Triple glazing, outward opening scandinavian style insulated doors. Minimum 400mm ceiling insulation with further 200mm rafter insulation. Keep higher ceilings otherwise you will cook if you have eliminated all drafts then most important MVHR (Partel balanced type) to keep the fabric of the building dry.
As you say to late anyway but do keep meticulous eye on you builders as many have been disappointed as the promised draft free home is freezing cold because its not been sealed properly due to bad workmanship. would certainly consider an airflow test when the build is finished so you can gauge how good the workmanship has really been.

 

[William G]

Everyone advised me not to dot and dab outside walls as they will eventually draw the damp through but to stud them with timber, insulate between the timber and just use normal plaster boards. Although a bit more fiddly it was much easier to square up and level the walls. I did dot and dab some internal walls and found it to be as fiddly as stone walls are never square or plumb and was using bags of the stuff!!

Pretty much did same and fully advise over dot and dab. My house was pretty damp. Timber framed and insulated all external walls nearly 20 years ago and no damp since. It was a thought at time but was told I would never regret it. Certainly haven’t.

 

[Kidds]

Mine is timber studded, insulated and ordinary plasterboard. Very eased with the results apart from it being a bit of a Faraday cage with the foil backed kingspan.
The one spot that was dot and dabbed is a mess as the dabs show through the paint.

 

[bobk]

Mine is timber studded, insulated and ordinary plasterboard. Very eased with the results apart from it being a bit of a Faraday cage with the foil backed kingspan.
The one spot that was dot and dabbed is a mess as the dabs show through the paint.

Should've plastered it , buy cheap buy twice