insulating single skin dwarf wall

21 Oct 2010
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United Kingdom
It has 3 outside single skin dwarf walls. Outside is a waterproof breather and pvc cladding.

Inside though, one wall is too close to the house door to offer any battens greater than 25mm.... is no air gap gonna be catastrophic if I use 25mm insulation?
Or should I just vapour barrier and clad? In which case should vapour barrier be behind battens against the wall or in front?

The other 3, I was gonna use 2x2 inch battens to hold 25mm insulation, thus 25mm ait gap.

Would the vapour barrier go infront or behind this? Im using pvc interior cladding sheets... thinking it should be cladding, barrier then insulation/stud work?
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You don’t need battens.

1. strip plaster back to brick
2. Use plasterboard foam to attach celotex pl4040 (or thicker) directly to the brick. Add a couple of frame fixers in each sheet (optional) for fire safety
3 fill the gaps with standard foam, scrim and skim
4 paint.

25mm insulation really won’t cut it. You ideally need 40mm or more. No need for air gap as long as it’s sealed properly with foam. The sheets have a built in vapour barrier
How dwarf? And on what?
the effort adding insulation may be pointless if the rest is glass.
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52cm high dwarf wall. Concrete blocks laid flat.
Roof is timber. Rest is glass.

Doesn't need to be megs efficient but just wanna hold some heat for a small period when we use it.

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