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Hi,
I'm having a cold flat roof installed. 100mm PIR board to be inserted between the joists and some form of insulation with plasterboard will need to be fitted to the ceiling.
I understand a vapour barrier needs to be fitted between bottom of joists (where the 100mm is inserted) and the finish insulated plasterboard of approx 30mm.
I get the impression a warm roof design has become the standard, is a cold-roof design acceptable in building regs?
To my knowledge, the vapour barrier comes on a roll which I can add as a separate item, but if I install a thermal plasterboard does it act as a vapour barrier anyway?
I watched a few video's on the subject and it mentioned that the 'vapour barrier' should not be pierced, if this is true how can a few spotlights be added?
I'm having a cold flat roof installed. 100mm PIR board to be inserted between the joists and some form of insulation with plasterboard will need to be fitted to the ceiling.
I understand a vapour barrier needs to be fitted between bottom of joists (where the 100mm is inserted) and the finish insulated plasterboard of approx 30mm.
I get the impression a warm roof design has become the standard, is a cold-roof design acceptable in building regs?
To my knowledge, the vapour barrier comes on a roll which I can add as a separate item, but if I install a thermal plasterboard does it act as a vapour barrier anyway?
I watched a few video's on the subject and it mentioned that the 'vapour barrier' should not be pierced, if this is true how can a few spotlights be added?