I shall be plasterboarding the ceiling of a dining room extension to my property soon.
I recall reading somewhere that the best approach for a good ceiling that doesn't crack is to put up two layers of 3/8" plasterboard with staggered joints.
There is also a loft conversion above, and I recall someone in this ng saying it is good practice to have a DPM above the ceiling, but below the joists, to avoid condensation in the loft.
My proposal is to use one layer of 3/8" foil-faced plasterboard put up first (foil-face down); then to tape the joints with aluminium foil tape; then to put up a second layer of plain 3/8" plasterboard with staggered joints. This will/should give me a strong, 3/4" plasterboarded ceiling with an integral DPM.
Is this a good plan, or is there a downside (other than the cost).
When fixing the first layer of plasterboard, should I butt the edges, or leave a small gap?
Same question for the second layer of plasterboard.
I'll be having a smooth skimmed plaster finish (not Artex). Which side of the lower layer of plasterboard should face downwards - the white or the grey? The joints will be taped, probably with open weave fibreglass adhesive tape, rather than paper tape.
Any comments/advice/warnings appreciated.
TIA