Hi looking for some advice on a few points,
We’ve reached this stage at the moment. (See photo) and trying to do as much of the build ourselves now that we have a watertight shell. (Naturally ventilated)
We’ve been doing a bit of reading but not really getting anywhere, more confused than anything.
I see a lot of different methods and materials being used when it comes to air tightness and VCL's
We are in the middle of adding pir to the sloping ceiling with 150mm in between the rafters and planning on maybe 60mm underneath with all joints taped to form the VCL, and battens to create service cavity.
1, Architect has specified 100mm loft roll in between rafters at ceiling level with 350mm over that, could we put pir inbetween rafters and tape over rafters to continue VCL?
2, does a parge coat act as a VCL for walls?

3,How would we go about making the expansion joint around first floor, floorboards air tight as we have missed the opportunity to use tony trays.
Thanks james