I have a vaulted ceiling in a new extension .It has100mm kingspan between the joist and building control say i need to now fix insulated plasterboard ,37.5mm total thickness . Is there a specific product that i use to affix the board ,if so what is it? Or do i use a combination of things, screws washers or whatever . Any advise appreciated thank you
Thanks Dan. Would i need to use any washers to spread the load to prevent the weight pulling the screw though the plasterboard.?