When we had our foundation replaced, it took about two days to
get all the equipment in place, but the actual jacking up of the
house took about half an hour to lift the whole thing 4 feet.

Rather than traditional screw jacks, they used centrally-
controlled hydraulic jacks so that the whole house lifted evenly,
no cracking, no split beams, doors and windows still opened and
closed normally, etc. Much faster and less disruptive than my
previous experience of lifting a house with screw jacks, and well
worth the cost of having a professional with the right tools.

The house was lifted on two steel I-beams supported near the
ends, around 30-foot span between jacks.

While it was up in the air getting the new foundation poured, we
took the opportunity to sister every floor joist whether it
needed it or not -- how often do you get a chance to work under
the floor with 4-foot clearance and no foundation walls in the
way?

--
is Joshua Putnam
http://www.phred.org/~josh/
Books for Bicycle Mechanics and Tinkerers:
http://www.phred.org/~josh/bike/bikebooks.html