Advice re-roofing a shed

Hi,

Have a pretty big garden shed where the felt on it has basically had it's day and is now coming away in my hands! Am planning to re-roof it but was looking for a bit of advice. Was recommended to use Paralon instead of felt but the cost is pretty heavy and the only sell rolls of 100m where I only need about 10m sq so the other thing I was advised to use was Casali shed felt? Anybody any experience of this? Would I need to put marine ply under the felt or is that over-kill?

We took off our felt too and, because the timber was wet/rotting at the corners (because is should have been done much earlier!) stripped off the timber base too. Then we used metal sheet cladding fixed directly to the rafters from the outside with self-drilling bolts. Straightforward and much much longer life - it'll see me out, I reckon. Various shapes and colours available so not too difficult to find something to suit. By adding 1 or 2 transparent sections along each side the rather dark shed is now a temple of light! Interesting sounds when it rains, of course, but nice...

Cheers Alastair!!! The shed itself is all wood (bit like one of those Sheomra things but not as fancy!!) which is why I'm not mad on the idea of a metal roof but I'll look into it