DIYbanter - View Single Post - Replacing corrugated asbestos-cement garage roof

wrote:
Chris Bacon wrote:
meow2222 wrote:
You can make your own flat fibre cement sheets if you want, it isnt
hard.

Interesting. How?

The material is simply fibre reinforced cement board. 1:3 mix with 5%
alkali resistant chopped glass fibres works fine. 1% polypropylene or
nylon fibre is also used for other purposes, though whether that gives
as much tensile strength as the glass I dont know.

The mould base is a sheet of glass, or ply with polythene on it. 6-8mm
wood is attached round the edges. The mix is made, it must be mixed
properly, and its tamped into the mould. Applying a sheet of polythene
on top will smooth it and keep it damp while it cures.

Flat sheet is less strong than corrugated, hence you may want to use
thicker sheet than the corru. It also looks a lot better.

NT

forgot to mention moulded sheets use a very fine sand. A mix of fine
and the usual would work.

NT