Do I need foil-backed plasterboard,or should I just tape the studs?

[OldBaker]

i have had a beautiful new cabin built, but I am boarding it out myself. The structure is timber and is stuffed to the gunwales with Celotex. The walls have 150mm Celotex panels which leaves a 10-20mm air gap between the front of the Celotex and the front of the studs. I have been advised that the joints between the plasterboard and the studs should be foil taped, but given the fact there is an air gap, would it be best practice to use foil-backed plasterboard. The heating is going to be underfloor electric, and while I am aware this is going to be really expensive to run, I want to make sure I am being as efficient as possible with the insulation.

So:
1) Just bang on the plasterboard
2) Tape the stud work and then bang on the plasterboard
3) Use foil-backed plasterboard

Many thanks

OB

 

[phatboy]

Makes no difference which you choose.... but normal board and a roll of 4" foil tape will be cheaper and take about 10 minutes longer to do!

 

[John D v2.0]

Sounds nice your shed.
What's on the other side of the celotex? If its a ventilated and drained cavity then there's no need to tape, although it would improve airtightness a little.
150mm is a huge amount of celotex, did you steal it or are you going for passivshed standard?