Roofing sheet tiles

[DrAndy]

Has anyone used the sheet cement tiles recently...the ones which are corrugated, about 1.20 by 0.5 metres?

There seem to be two ways of attaching them to the roof skeleton. One is by long clips, the other by screws?

Is one way better than the other?

the clips let the sheets move a bit, problems?

the screws could let some water in, even if fitted at the top of the curve?

[Dougal]

Mine's held with clips and in four years has had no trouble. These sheets will expand and contract, so trying to hold them with screws would probably accelerate cracking - would probably be a bit noisier at night as the sheets cool down as well.

[Thetyim]

Both clips and screws should come with two washers
One is metal the other rubber.
They stop any leaks.

I am guessing the next bit.
Screws are for a timber roof frame and clips for metal

[lom]

Screws are for a timber roof frame and clips for metal or timber roof frame.
There are 2 pre-drilled screw holes in the clips..

[DrAndy]

thanks for those replies

I have discovered a third method, for wooden roofs (as is mine)

they supply clips which attach to the rafters, then a screw goes into the clip. This is meant to prevent any cracking of the wood