shift and shoot sideways and KILL you.

Yup, I'm aware of this danger (which is why I asked!!!)

of spreader beams across several joists. (You DO know you don't use the
I-beam to jack with, right? You raise the house up, install the beam with
proper supports at correct height, and set the house back down on it.
Fractions of an inch clearance and all that.)

No, I didn't know you don't jack the i-beam. Thanks. What is a
'spreader beam'?

that a concrete floor isn't enough- you will probably have to punch holes in
the slab, and put in footers under where the posts will go.

Yeah, re-reading the engineer's report he says that in there. Guess I need
to rent a jackhammer.

I have a foundation guy coming to do other work, so I will get him to
quote me on this as well "just for laughts" ;-)