Christopher,

You need to establish the proper height. This can be done by a
string line stretched from outside wall to outside wall, an
optical instrument, or a laser. I assume the joists meet at a
center girder, usually tripled up dimension lumber the same size
as the floor joists. I assume you have concrete bearing pads in
the ground under this beam, probably every 8-12 feet.

If this girder is down more than an inch, do not plan on pushing
it all back up in one day. It took many years to settle, if you
shove it back up quickly you will crack plaster, walls, etc. I
would plan on using dry laid solid patio blocks or similar to
replace the existing props, they usually come in nominal 2, 3, and
4" thickness in 8x16 units; buy some of each. Cut up an
assortment of wood shim pieces. Make them 8x16, using 3/4, 1/2,
1/4 thicknesses. Create a bearing pad: a piece of 1/2" steel
plate or tripled up layers of 3/4 plywood, at least 12x12, bigger
if you can work with it. I would use a hydraulic jack on this
bearing pad close to the footing pad, probably 25 ton capacity or
more, with another piece of steel at the bottom of the girder to
keep the jack top from crushing the girder. Jack the girder up
until it just unweights the existing junk. Build up your blocks as
close to the bottom of the girder as you can get in full block
units. Plan on raising each bearing pad about an inch, so jack up
enough to slip in one more 1 5/8" block and the difference in
wood shims. Let everything rest after you have done all the
footing pads, at least a week. Plan on raising the bearings about
an inch each time. They will pop and groan as they are forced
back into position. Remember, you are raising any bearing walls
and ceiling structures that bear here at the same time.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Christopher Flynn" wrote in message
...
I've got an old (1958) wood frame home that was built on a
hillside, and
the floor is sagging in the middle of the house. There's a
rather large
crawl space under the house( floor), about 7 feet of space in
the
slopping area. You can see where other owners had put timbers
(4"x4") on
rocks and then proped up againts the sagging floor frame.
But how can I get the floor frame back at the right
height???...with a
jack of some sort?...or would a professional outfit like Power
Lift be
needed? I would hope to avoid PL because of the $$$ involed.
Has anyone here delt with this sagging floor problem? I feel
like the
floor will cave-in if nothing is done, it's in a high traffic
area and
you can feel the slope down in the floor. I wouldn't say the
wood is dry
rotted but it's has seen some better days....just needs
repositioned
....I think?
Thanks for any help.