On 03/03/2011 20:27 Jim K wrote:

In any case in such a "no access to" space a good thickness of
"special offer" glass wool will probably be a damn sight easier to
obtain, transport and fit successfully than any board/sheet
material....it may even be cheaper too but ICBA to find the
comparitive figures....

25 sq metres of 200mm cost me £15: recent B&Q offer.

Is there a 'preferred' felt with which I should 'repair' the roof after
I've finished?

anything modern (i.e. plastic) will outlast anything
"traditional" (e.g. sarking felt) - I'd generously overlap the old
gear to minimise leak risks....

I'll look for something plasticky then! And take the advice on a
generous overlap: there'll be plenty as I won't be cutting a roll sized
hole!

--
F