existing decking is chipboard and has leaked in places. Hot laid felt stoned with grano chips. Loath the idea having to strip it as its integral with next garage.

Roof structure : 4 x 2 in 12 foot lengths total run 32ft on 3 cross supports of 6 x 2inch across the 10ft width.

I've the idea of cross batten the existing roof cover with 2 x 1 battens then lay new O.S.B decking plus the new felt and stones. Would extra supports be needed to cater for extra weight?

bob, September 2009