Replacing chipboard on flat roof

Rob,

Would you consider replacing with colour steel roof sheets such as

If not, the you should replace it with 22mm WBP external grade plywood - and refelt the roof.

Cash

I thought of plywood, but a) 22mm is way to heavy on the pocket for a roof of this application and size and b) it's horrible stuff to nail into from past experience.

I realised after I'd posted that I'd used Onduline on my workshop roof and found it so easy to apply and overall cheaper than proper felting, leaving aside the effort of doing a good roof felting job. If nothing else comes up I'll probably go that way - may be necessary to add a frame timber of two but all that will be easy.

Thanks for your reply.

Rob

Chipboard does fail faster once it gets wet, but ply and osb dont extend the life by much, and chip is still a usable option, and of course cheap as chip.

NT

IME OSB should see you out (and could then be used for your coffin!). I've had OSB unprotected outside for about 20 years. It had spent 2 or 3 years covering a windo next door then, about 20 years ago, I used some of it in a very testing way: in shade, horizontal and on to of a water butt. It's slimy on top and 'splintery' underneath but still sound.

The correct grade is needed - I don't know what it is that I used.

How did you know ?

Rob

Oh, sorry, couldn't find the symbol for 'muffled voice' ;-)