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Internal wall insulation for room with mixed wall types, and what to do for walls underfloor
I have an old solid brick house c 1900 that has been extended over the years. I'm renovating the 1st floor bedrooms with internal SWI, which in all cases have 2 external solid walls, 1 internal solid wall and 1 internal stud wall.
Could I use the same wood fibre boards insulation all the way around the room? or should i be looking at wet-process for the solid walls and dry process for the stud walls? or even dry-process for the internal solid wall?
I am thinking of going for 60-100mm on the external walls and 60mm on the internal walls.
Also what do you advise for the wall areas below the floorboard? should the insulation be taken all the way down to the ceiling below, or does other approaches need to be taken to keep any moisture away from the joists?
For your external walls I'd suggest either 60 or 100mm Beltermo Room wood fibre boards (dry process, square edge board) and then for your internal masonry partition, you only really need 20mm boards to prevent thermal bridging. For your internal stud partition you will need a T&G board and so I'd suggest the Beltermo Ultra boards, which start at 40mm thickness.
The floor zone should always be insulated so ideally you should cut your floorboards back and take the insulation around the floor joists and down to the ceiling. It would also be best to cut the ceiling back when you insulate below the floor and then join up the two layers.
The spec for the external walls would be as follows:-
Existing wall, plaster removed
Hope that helps.
Not so much one over the other, more I think this would be the most economical and effective solution for you.
Hope that helps.
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