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?

Seems like the obvious route is to jack only one side up, add
brickwork, let it set, then jack other side, add brickwork, and walk
it up like that. I assume you'd need to attach a very hefty beam along
the length of the thing first so that all the frames are lifted, no
use just lifting some of them.

Should work OK, I'd try that anyhow. Guarantees are a whole nother
matter tho. Better make sure you got hard hats on!

Regards, NT