On Wed, 30 Jan 2008 20:38:56 GMT, "KinRsole"
wrote:

My garage roof is made from that fibre board/cement board stuff (sorry I
don't know the correct term but you know what I mean)

A couple of the panels have now cracked.

Is there a way to repair these.

I did think of filling the crack with some sort of silicon or sealer both
from the outside and inside.What type of sealer should I use?

I would use car body filler. To stop the crack you drill a largish
hole right at the end of the crack. That knackers it as it can't find
it's way any further.