I'm gonna go and mount my Panny, probably with the lmp mount. Simply question is how do i attach it safely to the ceiling? Ceiling seems to mainly consist of thin layer of crumbly plaster and above that are the wooden rafters. I guess I will need to use a block of wood and screw that to the rafters and attach the mount to that? Any tips or ideas would be of great use. A projector landing on my head mid film might spoil the movie!