fixing heavy unit to wall with large cavity?

[yasee]

I have a large, extended wall of plasterboard, which is approx 3 inches away from the 1st layer of cavity wall. I have to fix a heavy unit to the wall, and If I use a rawlbolt, how do I get the bolt to stay in the brickwork, rather than 'creep' up the thread when turning it, and forcing it into the plasterboard cavity? I am worried that the bolt will not open in the brick work?

[thedoctor]

Its no good using any type of bolt in this situation as whatever you "hang" on the fixings will simply bend them down and they will drop. To fix anything heavy to a wall which has been dry lined away from the masonry surface, its best to cut away some dry lining, fix timber directly to the wall using our fixing to masonry project, then fix the uinits to the timber. The plasterboard can be cut neatly, the timber painted to match the wall (not that it is often seen) and any gaps filled with flexible filler, or decorators caulk. You can find this in our poroject called filling gaps around the home.