As I am ready to invest considerable cash into lining and insulating an outbuilding, and given the wealth of often contradictory advice as to how best to do this, I am desperately seeking professional advice for confidence in a strategy that's sound for the longer term.
I have an 18ft x 9ft garden outbuilding - typical 20mm T&G, suspended wooden T&G floor recently reinforced with 18mm WBP ply sheet, and T&G apex roof.
The office section is 12ft x 9ft for which I wish to concentrate on lining and insulating the walls and roof. The adjoining 6ft x 9ft shed section will not be insulated.
The walls have vertical studs 60 x 40mm at varying centres, providing 60mm wall cavities around the room. The apex roof has 40 x 40mm supporting studs running lengthways to the building with a truss in the middle.
Although the walls and floor are tanalised, I believe the T&G roof and support timbers aren't.
So, how should I insulate the walls? Fill (almost) the wall cavity sections with 50mm Kingspan/Celotex and panel over the top of an internal vapour barrier laid over the insulation/timbers, or add further horizontal timbers for the insulation/paneling - leaving the existing wall cavities as breather gaps? Some say fill the cavity completely, while others say leave a breather gap to avoid trapping damp. Some say line the exterior walls with breather memberane, and others say it isn't necessary.
Regarding the roof... same considerations.
I would so appreciate some direction from professional bods 'in the know'. I'm much less interested in saving cost (without going stupid) and more interested in general longevity and effectiveness. It's a serious project that I want to get right, but has stagnated until I can establish direction and generally consistent advice.
Many thanks in advance.
FJ
I have an 18ft x 9ft garden outbuilding - typical 20mm T&G, suspended wooden T&G floor recently reinforced with 18mm WBP ply sheet, and T&G apex roof.
The office section is 12ft x 9ft for which I wish to concentrate on lining and insulating the walls and roof. The adjoining 6ft x 9ft shed section will not be insulated.
The walls have vertical studs 60 x 40mm at varying centres, providing 60mm wall cavities around the room. The apex roof has 40 x 40mm supporting studs running lengthways to the building with a truss in the middle.
Although the walls and floor are tanalised, I believe the T&G roof and support timbers aren't.
So, how should I insulate the walls? Fill (almost) the wall cavity sections with 50mm Kingspan/Celotex and panel over the top of an internal vapour barrier laid over the insulation/timbers, or add further horizontal timbers for the insulation/paneling - leaving the existing wall cavities as breather gaps? Some say fill the cavity completely, while others say leave a breather gap to avoid trapping damp. Some say line the exterior walls with breather memberane, and others say it isn't necessary.
Regarding the roof... same considerations.
I would so appreciate some direction from professional bods 'in the know'. I'm much less interested in saving cost (without going stupid) and more interested in general longevity and effectiveness. It's a serious project that I want to get right, but has stagnated until I can establish direction and generally consistent advice.
Many thanks in advance.
FJ
