I don't really see why not. Hydraulic lifters are available. Would need a
few load spreading beams to give stability. I've seen a whole house lifted
and transported in the US, so a roof ought to be easy! I'd expect the ridge
tiles to come unstuck and need recementing. Anyway if it did fall down, you
just say the appropriate words and put it back together again! It does have
the advantage of being able to work in the dry. Wind loading might be a
stability problem. Is it tied into any other roof/wall?
Regards
Capitol

David @nospam.cod wrote in message ...
I plan to increase the height of my garage by about 6' to build an extra
storey, I'll be re-using the existing roof as it is, instead of
dismantling the whole thing and then rebuilding I thought I might jack
the roof up and slip some extra wall underneath, what do you think?


--
David