Replacing lathe and plaster

[Macsky]

Looking to replace some ancient lathe and plaster with new stud walls in an old stone built house. What thickness of stud/kingspan is recommended? Obviously the thicker the better insulation wise, but there must be sweet spot. 100mm?

 

[zero]

We've just done similar, loadall bucket outside the window to shovel the rubble into.
Then builders used 2x2 wood I think but could have been 3x3 as I didn't measure it, fastened at 600mm spacings with 50mm kingspan between. Then plasterboard to cover it in. We staggered the electrical sockets to stop noise transfere and as they weren't supporting walls we re built them where it evened up the room sizes a bit.

 

[Mur Huwcun]

Builder merchants will have CLS timber in 2.4m lengths specially for stud walls. They will be equivalent to 4x2 or 3x2 so the choice is yours. If space is not an issue go for the 4x2s.

 

[Alchad]

I did the same when we moved here 20 years ago. Used 2 x 2's and 50mm Kingspan . Obviously thicker insulation better but then you reduce room width. Things to bare in mind are getting battens level and vertical and horizontal, you need to pack out behind the fastenings (I used 100mm frame fixings), then use expanding foam in gaps between the battens and the old wall.

 

[Hampton]

Looking to replace some ancient lathe and plaster with new stud walls in an old stone built house. What thickness of stud/kingspan is recommended? Obviously the thicker the better insulation wise, but there must be sweet spot. 100mm?

If it’s sandstone the insulation won’t need to be very thick at all.
Also, I’d think about batons, then thermal board on the top, to prevent cold spots transferring from the wall through the insulation/plasterboard
I know this sounds unlikely but it can happen.

 

[quavers]

just done this in a 300 yr plus old farm house with uneven walls stud framing close to the wall as possible , 75mm king span on most of the wall the odd bit down to 50mm still allowing a air gap between the kingspan and wall , house now holding the heat much better now and rooms not now going cold soon as the heating going off

 

[Macsky]

just done this in a 300 yr plus old farm house with uneven walls stud framing close to the wall as possible , 75mm king span on most of the wall the odd bit down to 50mm still allowing a air gap between the kingspan and wall , house now holding the heat much better now and rooms not now going cold soon as the heating going off

Yeah this is what’s needed here, a decent gap between the stone work and the internal stud, need to keep the air flowing about the old walls as they’ll never be waterproof, that’s what did damage to a lot of the lathe as bits of the plaster was falling off the back of it plus mortar out of the walls building up between the stone and the lathe and just creating a bridge for damp to travel a rot everything.

 

[dubs]

when we did the up stairs of our house a few years ago the joiners did a stud wall, 3x2 i think as the ceiling height here is 3mtrs, as close to the stone wall as possible but still leaving a air gap, fitted 75mm kingspan between studs then foam glued a plaster board sheet with a 25mm kingspan bonded to it giving us 100mm of insulation.
Upstairs is now a usable space, retains heat a lot better. We used to have the heating on in the morning for 3-4 hours before we rose but now most days its off apart from really cold days
The heat retention alone was worth the cost
Still to do down stairs but will do the same again

 

[Macsky]

when we did the up stairs of our house a few years ago the joiners did a stud wall, 3x2 i think as the ceiling height here is 3mtrs, as close to the stone wall as possible but still leaving a air gap, fitted 75mm kingspan between studs then foam glued a plaster board sheet with a 25mm kingspan bonded to it giving us 100mm of insulation.
Upstairs is now a usable space, retains heat a lot better. We used to have the heating on in the morning for 3-4 hours before we rose but now most days its off apart from really cold days
The heat retention alone was worth the cost
Still to do down stairs but will do the same again

Yeah the upstairs would be near the top of the priority list. It’s Baltic in the winter, but if the sun comes out and hits the slate roof it doesn’t take long to become unbearably stuffy.

 

[pycoed]

Yeah the upstairs would be near the top of the priority list. It’s Baltic in the winter, but if the sun comes out and hits the slate roof it doesn’t take long to become unbearably stuffy.

Iwas watching Ants Pants on Youtube the other day in Estonia. He refurbished & insulated an old log cowshed with a LOT of insulation - about 10" IIRC. At this stage the building is not heated at all. He was showing the temperatures in winter when -19 deg outside & inside it was -1! In summer when 24 deg outside it was 6deg inside - quite a demo of the value of insulation.

 

[wdah/him]

when you do all this insulting to walls do you do any more tot eh ceiling? Or roof maybe be better to stop heat lose that way, just curious as we have an old house here i would like to renovate but probly better rebuild. if i do it i will ahve to rebuilt the kitchen and bathroom that dad build on to it years ago.

 

[Macsky]

when you do all this insulting to walls do you do any more tot eh ceiling? Or roof maybe be better to stop heat lose that way, just curious as we have an old house here i would like to renovate but probly better rebuild. if i do it i will ahve to rebuilt the kitchen and bathroom that dad build on to it years ago.

Roof would be the first priority really

 

[suffolksmallholder]

I gave up with any sort of timber dry lining and simply removed everything, rotten wood-wormy under spec timber floor joists & rotten floor boards.
The main floor and its many levels was removed and subbed to an appropriate point to allow well compacted type 1 followed by two layers of reo mesh on suitable chairs embedded in 200mm of concrete.

All old plaster was removed from the exterior walls.

New masonry walls were sprung off this concrete raft using 100mm Celcon blocks with 32 graded 100mm insulation. 38mm insulated plasterboard will cover the masonry and my GSHP should keep the interior at 22 degrees if I’m lucky. I have failed if it will only reach 19 degrees.

Use SS screws if you do dry-line but IMO this is only really a short term fix.
SS

 

[Northern territory]

I gave up with any sort of timber dry lining and simply removed everything, rotten wood-wormy under spec timber floor joists & rotten floor boards.
The main floor and its many levels was removed and subbed to an appropriate point to allow well compacted type 1 followed by two layers of reo mesh on suitable chairs embedded in 200mm of concrete.

All old plaster was removed from the exterior walls.

New masonry walls were sprung off this concrete raft using 100mm Celcon blocks with 32 graded 100mm insulation. 38mm insulated plasterboard will cover the masonry and my GSHP should keep the interior at 22 degrees if I’m lucky. I have failed if it will only reach 19 degrees.

Use SS screws if you do dry-line but IMO this is only really a short term fix.
SS

Snap! just done exactly the same and glad we have done it even though it was a bit of an emotional pull to start with

 

[quavers]

if your house is a traditional scottish house 1 1/2 story , for up stairs rooms clear off plaster and larth , we fitted 100mm kingspan between the roofing timbers on the slope again leaving room for a air gap , on the horizontal part of the roof ( the flat bit) we used doubled up glass wool , joiner who did the job advised that they always do this to allow every thing to breath and allow moisture to rise up and away .

 

[GEMS]

Fitted a stone cottage with 75mm celotex backed with plaster board , amazing insulation.
Go as thick as you can get, insulation is cheap compared to yrs of energy purchase ........
If you keep existing electrical boxes you can get 75/100mm extension screws to get sockets to reach !!

 

[miniconnect]

pull it all out, dump trailer under the window and a damn good dust mask. the black stoor behind it is horrible.
I spent the last 2 years doing this whole house. 4x2, 100mm insulation. vapour barrier, and a good gap between it and the stone. don't be greedy, make sure there's no moisture bridge at all.
It's too bloody warm now. electric storage heating at 16degrees and I can't sleep at night sometimes with it too warm. worth the months of my life and every penny it cost tho.

 

[Macsky]

The floor joists are rotten where they meet the old stone wall, likely need to take them out and concrete the floor, would I be right in thinking there should be a gap between the concrete and the walls to let any future leaks/dampness (just sorted the chimney) get to ground rather than hitting the floor and heading inwards, as was happening?

The kind of stonework and weather here is always going to leak at some point in life, no point in it affecting anything tin doesn’t need to is my thinking.

 

[miniconnect]

The floor joists are rotten where they meet the old stone wall, likely need to take them out and concrete the floor, would I be right in thinking there should be a gap between the concrete and the walls to let any future leaks/dampness (just sorted the chimney) get to ground rather than hitting the floor and heading inwards, as was happening?

The kind of stonework and weather here is always going to leak at some point in life, no point in it affecting anything tin doesn’t need to is my thinking.

we had similar, although the joists weren't actually within the walls, they sat on wall plates and dwarf walls. house is built into a hill so very deep at the front of the house. had to put in a drain for water and more ventilation. dry rot was the biggest thing.

if you fill yours in, I'd consider underfloor heating and a screed. plastic under concrete with enough to go up the wall a bit wouldn't be a bad idea.

 

[Macsky]

we had similar, although the joists weren't actually within the walls, they sat on wall plates and dwarf walls. house is built into a hill so very deep at the front of the house. had to put in a drain for water and more ventilation. dry rot was the biggest thing.

if you fill yours in, I'd consider underfloor heating and a screed. plastic under concrete with enough to go up the wall a bit wouldn't be a bad idea.

Yeah it’ll most likely be made up for underfloor heating, not sure it can work off the old gravity fed system but will be done for the future at least.