Well, we were about to start putting up the walls (Knauf 55mm Polyfoam linerboard) in the garage on Sunday, and just as we got to putting one up against the wall, we noticed that they had bowed outwards by about 10mm in the middle.
We have now laid it all back down on the floor, foam downwards, and put a few pieces of plasterboard in strategic positions to attempt to gently bow it back the other way. Any other suggestions as to how we can straighten this out?
Cheers
JW