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.

I thought all glass was "alkali resistant"?

? 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.

a) I've used this in render, b) getting it evenly spread in the mix
is nigh impossible, c) I doubt it very much.

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.

I assume this is all theoretical. Hm?