I had a very a large quote for removing tiles, adding felt and replacing tiles - it assumed 1/3 would be broken. Is there an alternative, placing some sort of waterproof insulation board from inside between the rafters, avoiding the need to touch the tiles?

Chris, September 2009

No! No! No! not foam fill never liked it never will, yes it may be a good and cheap idea but it causes no end of problems removing tiles cracked or flaking cause by frost, and makes it a lot harder to detect where leaks come from, Yes foam filled roofing does leak.

My advice is contact your local building conrol office ask about grrants for a re-roof under engergy saving if the loft is not inulated betwen ceiling rafters you may be able to add that too. plus cavity wall insulation.
it's up to you.

bob, September 2009

If you are suffering water ingress then a roof strip is really the way to proceed. However, if you just want to stop draughts as there is no underfelt, consider having the roof sprayed with a polyurethane foam. The slates need to be good though or else wood rot will result if water gets through.

John, September 2009