Internal insulation for solid brick walls - stud or insulated plasterboard?

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Our house is 1860 solid brick and both the soaring gas prices and the recent heat are making us think we should hurry up and insulate the rooms we use most, we were going to slowly do this as we redecorate each room but doing anything before winter would claw back some costs in heating savings.

Just wondered on thoughts about building a traditional stud wall with insulation in Vs PIR-backed insulated plasterboard which would be dot'n'dabbed directly onto the wall. A stud has the advantage I can do some/all of it myself and presumably leave the existing wall as-is and hide it. I've never done DnD so I'd get someone in (our plasterer is good at it) but it goes up super quick, though I don't know if it can affix directly to painted/wallpapered walls or they'd need stripping.
Assume a cost saving on DnD since you don't need all the timber.

Is there a good argument for a stud or is affixing directly to the wall the obvious way to go?
 
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Fix battens to the wall, insulate with PIR between and across. No voids.

D&D needs to be direct to bare wall and is not as efficient or cost effective for the mess and effort.
 
Fix battens to the wall, insulate with PIR between and across. No voids.

D&D needs to be direct to bare wall and is not as efficient or cost effective for the mess and effort.
Interesting, thanks. So I might for instance use 2x2 battens with 50mm insulation in-between, and then 50mm insulated plasterboard on top?
Does insulating across the battens make a substantial efficiency difference or is this primarily to avoid other issues like condensation?
 
It avoids getting dark stripes in the decoration.

Yes you could do as mentioned, but check the cost of insulated plasterboard against the cost of PIR and plasterboard. Bear in mind that you'll need PIR half to two-thirds as thick as the insulation on plasterboard, or you get more efficiency for the same thickness.
 
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I have a similar conundrum. Gable end walls in a loft conversion to insulate.

Insulated plasterboard is stupid expensive so ruled that out. Initial thoughts of battening out and then insulating over the top are going to loose me 10cm each side. Was going to just try for 50mm straight onto the walls to avoid the batten cold bridge. What’s that sticky foam like? Can it then stick plaster board straight to celotex? Without battens won’t have anything to screw boards to.
 
'Thermally broken' studs seem to be a thing in the US (although they are whole wall thickness):
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I have heard mention (probably from this forum!), of cork insulated structural studs - but I haven't found them anywhere.

It seems odd, that as so much of the UK's housing stock could benefit from extra insulation, such things as 'insulated structural studs' aren't available on the DIY market. Is this an idea for Dragons Den? ;)
 
I have a similar conundrum. Gable end walls in a loft conversion to insulate.

Insulated plasterboard is stupid expensive so ruled that out. Initial thoughts of battening out and then insulating over the top are going to loose me 10cm each side. Was going to just try for 50mm straight onto the walls to avoid the batten cold bridge. What’s that sticky foam like? Can it then stick plaster board straight to celotex? Without battens won’t have anything to screw boards to.
I would imagine you can make your own insulated plasterboard but I don't know the time and fuss would be worth the saving.
It might be worth checking out insulation 'seconds' on the real thing for a good deal
 
I would imagine you can make your own insulated plasterboard but I don't know the time and fuss would be worth the saving.
It might be worth checking out insulation 'seconds' on the real thing for a good deal
Time and fuss to save a fiver is right up my street. Tighter than a gnats chuff.

So, the question….. can celotex be stuck to brick with sticky foam, then board stuck on top with the same stuff ….. no screws?
 
Time and fuss to save a fiver is right up my street. Tighter than a gnats chuff.

So, the question….. can celotex be stuck to brick with sticky foam, then board stuck on top with the same stuff ….. no screws?
Yes but it could all drop off
 
Time and fuss to save a fiver is right up my street. Tighter than a gnats chuff.

So, the question….. can celotex be stuck to brick with sticky foam, then board stuck on top with the same stuff ….. no screws?
To bare brick?
 
Time and fuss to save a fiver is right up my street. Tighter than a gnats chuff.

So, the question….. can celotex be stuck to brick with sticky foam, then board stuck on top with the same stuff ….. no screws?
Gyproc 63mm is £67 a sheet use foam adhesive and mechanical fixings - concrete screws at 10 per board with a cup washer, the dig just under the surface so you can either plaster or fill them.

Or just stuck kingspan or your choice of foam board to the wall and then batten over the top,there won't be any coldsposts as the wall is completely covered by the foam, the batten - roofing is fine - does two jobs it mechanically fixes the foam to the wall and gives you something to screw the plasterboard to. Just screw through the batten and kingspan into the wall using self cutting concrete screws - drill a hole then impact in the screw no need for plugs. Fill any gaps with spray foam and foil tape the joints,
 
Gyproc 63mm is £67 a sheet use foam adhesive and mechanical fixings - concrete screws at 10 per board with a cup washer, the dig just under the surface so you can either plaster or fill them.

Or just stuck kingspan or your choice of foam board to the wall and then batten over the top,there won't be any coldsposts as the wall is completely covered by the foam, the batten - roofing is fine - does two jobs it mechanically fixes the foam to the wall and gives you something to screw the plasterboard to. Just screw through the batten and kingspan into the wall using self cutting concrete screws - drill a hole then impact in the screw no need for plugs. Fill any gaps with spray foam and foil tape the joints,
Going back to my wall lining, I was wondering about your 2nd suggestion being equally applicable to me? Instead of battening and then insulating between and having to put additional insulation on top - could I line the whole wall with PIR boards, batten on top and then affix plasterboard?

There would be a void between plasterboard and insulation (the depth of the batten) but if I'm honest, when you should or shouldn't have voids and breathable/non-breathable membranes is something I find pretty confusing. I think a void on the inside (warm) of the insulation should be fine?
 
For my initial thought of sticky foam, I was thinking of using that for the lot. Foam the PIR to the brick, then foam the plasterboard to the PIR. No studs at all to cold bridge, cover up or fix into. According to the advertising blurb I’ll be laughing all the way to saving 2” on each wall….. before the lot drops off in 6 months.

Might do a test patch, although that won’t test longevity. But heegh, this stuff has been around ages and I’ve not seen any outcry of failing foam. Got a few weeks before I decide if I’m brave enough.
 
I think you could get away with 25x50 or 25x38 retaining battens so you're only saving an inch but those mechanical fixings are quite pricey. I think testing it on a 50x50cm mockup you can glue on and try to pull down might be sensible :)
 

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