i'm putting 2 layers of plasterbaord onto a false ceiling. one layer of plasterboard is foil faced for a vapour check. should i put the foil faced boards on top (ie foil face next to insulation) or the foil faced boards as the bottom layer (ie foil face sandwiched between two layes of plasterboard) ... does it matter.
thanks
Why are you putting up 2 layers of plasterboard and why are you using foli-backed plasterboard?
2 layers for improved sound insulation and as a fire check between properties of differing occupancies. vapour check for moisture / condensation control (this isn't unusual) its a cofeeshop, our sitting room is directly above. the ceiling has been lowered with a timber stud frame with rockwool flexi between the studs (more sound insulation + thermal insulation)
I don't think it matters really, but I'd personally put the foil up first, foil-to-insulation.
Is the stud frame decoupled from the joists above? For best sound insulation it should be a free floating frame supported only at the walls). Make sure the edges (board/wall), and the places where lighting cables come through, are well 'caulked' so the are no acoustic paths through.
I (for one) would be interested to hear how well you find the sound insulation works.
Robert
OK, understand your reasons now, which make sense (and comply with building regs). I agree, foil-backed first.
Its even better if you build new stud walls and isolate it from the walls too (box within a box).
Its worth remembering that foil backed plasterboard impedes wireless like WiFi, DECT, etc. If you want to use these between the areas use a polythene membrane to minimise problems.
Sounds as if you have done the job well then. You should get about
25dB extra attenuation at mid frequencies - that's better than a good pair of foam ear plugs.yes please I'd be interested to know how it works out either here or if not you can email me on laws at bcs dot org dot uk
Robert
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