[Alan]

So I found someone who is could lend me a couple of screw jacks for a while until I get this floor problem fixed.

Other threads found here : http://www.diychatroom.com/f19/so-ive-decided-i-need-jack-up-floor-165230/


Well I crawled underneath there and it turns out I have roughly 18" between the dirt and the bottom of the beams, and the screw jacks that I'm borrowing are 16" tall at their lowest setting.

Suggestions were to use railroad ties to set the jacks on, but seeing as I only have 2" of space, i'm looking for some new suggestions.

Will a single thickness of 2x12 be enough to keep the jack from sinking in the dirt?

 

[DangerMouse]

You could do that, but I'd recommend using PT 2x12 chunk. If it were me though, I'd use a 12x12 square of the 1/4" steel plate I have laying around. Got any steel plate handy? Need a hunk?

DM

 

[joecaption]

What is it your really trying to do Alen?
Just trying to lift one joist at a time is not the best way more often then not and without a steel plate on top of the piston it's going to act like a cooke cutter and crush the joist.

 

[jomama45]

Will a single thickness of 2x12 be enough to keep the jack from sinking in the dirt?

Short answer: YES, the longer the better..............

 

[joecaption]

http://www.northerntool.com/shop/tools/product_200305499_200305499
This is what I use in tight places.

I use cut off LVL's to set it one.

 

[gregzoll]

Pancake jacks would work better than a normal bottle jack. http://www.cylinderjacks.com/shop/index.php

 

[BigJim]

Be careful, that single thickness of 2X12 can pop along the grain with a little pressure on it. If at all possible use at least 2 thicknesses and run the grain in the opposite direction of each other, also like said, use a steel plate on top and bottom if possible but especially on the top. If your screw jacks are like the ones I use to have you are going to have to put some serious pressure on them to get them to work.

 

[oh'mike]

Steel against steel is slippery-----be careful-----if the jack is out of plumb to the top steel plate it can pop out----

I know this is a one time deal---but a plate with a ring or stops welded on is much safer.

How heavy and how high is the lift?

 

[joecaption]

That's exactly what we ended up doing.
Took 2" steel pipe and welded a 1/4 thick plate on it.
Now it stays in place.

 

[Alan]

How heavy and how high is the lift?

I don't know what the rating is but it was being used to jack up a 2 story barn prior to getting my hands on them. They are ~ 16" tall

 

[oh'mike]

That is a great jack---I was asking how high are you lifting your structure?

If the lift is not unbelievably heavy---and you can't weld stops to your top steel plate--at the very least put a block of plywood between the steel plate and the jack---it will crush---creating a pocket

Gluing it to the steel before you start would help.

Steel on steel is slippery---we used to 'fine tune' the location of mixing tanks the size of a tanker truck, by driving thin steel wedges under the four legs--then hit the legs with our butt---and the tanks would slide right off the wedges.

 

[BigJim]

That is a great jack---I was asking how high are you lifting your structure?

If the lift is not unbelievably heavy---and you can't weld stops to your top steel plate--at the very least put a block of plywood between the steel plate and the jack---it will crush---creating a pocket

Gluing it to the steel before you start would help.

Steel on steel is slippery---we used to 'fine tune' the location of mixing tanks the size of a tanker truck, by driving thin steel wedges under the four legs--then hit the legs with our butt---and the tanks would slide right off the wedges.

I was thinking adding a ring to the steel plate when I made the post and should have said so but didn't, Mike is dead on, I have had jacks slip because of the steel and it is scary, you really don't want to get hit with a jack coming out from under pressure, That alone is enough to scary the dickens out of a person but the house dropping back down with a loud thud just adds to it, no fun at all.

This is like the jacks I had only they were bigger and hard to use.

 

[AndyGump]

I am working on a house right now lifting the floor joists only about 1/4", just enough to take the weight off the existing foundation.

I use a couple of 20 ton bottle jacks, a 4 x 6 DF beam, two 12" concrete piers and some cribbing made from 4 x 6 PT lumber.

If I were you, I would dig out the ground enough to allow the 4x6 cribbing, place three one way and the other three the opposite direction.

Set the piers on the cribbing with enough room for the bottle jacks, place the 4x6 DF beam on the piers then start lifting the beam with the bottle jacks.

Block with some 4 x s and shims, let the jacks down until the beam makes full contact with the blocking on the piers and go to town on fixing the foundation.

Then go to town and get some beer.

Andy.

 

[[email protected]]

I am new to this forum group, But i can tell you from experience when it comes to jacking up any part of a structure that it is a good idea to make sure what ever it is you are pushing against can not kick out!

If you do don't do this do not get your head any where near the jack. I can tell you and send pictures if you would like on the damage it can and will do if the jack kicks out.

Do not get hit in the head with 8 thousand tons of force. This happened to me and I broke some teeth. It hurt a lot for a lengthy amount of time even after the damage was fixed. Please do not make the same mistake I made!