"Simon" wrote in message
oups.com...
Hmm so it seems the concensus is that the fibre cement is the better
material, so I'll go with that approach.

It's different. For some applications, it may be better, for others,
e.g. as I suggested, long, low-pitched roofs, it may not be. It's
certainly expensive and heavy.


Is it actually "better" than
the old asbestos stuff, or could my original one just have been badly
installed? I say that because the last roof is probably only 10-15
years old, way less than the 40 years lifetime suggested for fibre
cement.

If it's that new, I'd be very surprised if it is asbestos-cement. Could
second-hand sheets have been used when it was built? There was a
thriving trade in s/h asbestos-cement sheets long after fibre-cement
became the new norm.

If they really are that new, and have failed, I'd be looking very hard
at the underlying structure, to see if it is adequately stiff. If it
isn't, then you've either got to strengthen it or take a chance with a
less brittle material. Or stop exercising the elephant on it.

If you do use fibre-cement, think hard before painting the underneath:
if you make it any less absorbent, you'll get condensation, just like
you would with steel sheets.


--
Kevin Poole
**Use current month and year to reply (e.g. )***
Car Transport by Tiltbed Trailer - based near Derby