Need advice for supporting Concrete porch for wall repair

[mmm073]

I am planning on replacing a block wall that supports a 16x10 concrete slab porch on the front of my house. The 16 foot length wall is bowed in at the middle by about 2 inches, I was looking to take the wall completely out, and replace it with new block. the concrete slab is 4" thick, and is 16 feet long by 10 feet wide. It is currently supported by the wall that I am looking to remove, and by 3 concrete pillars on the opposite side of the wall. I am looking for advice on how to jack / support the concrete slab while the outer wall is replaced. I have 2 2x6 by 8 ft beams, and 4 metal jack stands. I was going to place the 2 2x6 boards 2 feet in from the outer edge of the concrete and use a jack to lift the wood and place the metal supports under the wooden beams to get the weight off of the wall so it can be replaced. does anyone have any suggestions or advice for the beam placement, or positions that can make the supporting of the slab safer / better?

 

[Ron]

Why not replace small sections of the wall at a time, starting in the center and working outward? The slab will span several feet temporarily without load on it, since it is a reinforced, off-grade slab.

You should be able to jack the slab slightly to remove the existing wall. Don't jack it more than about 1/8", as you might start to crack the slab if it is restrained in other locations.

Be sure you shore the entire area underneath if you are going to be working under there. That 16'x10'x4" slab weighs roughly 7500 lbs. You don't want that coming down on you or your fingers!

 

[mmm073]

as far as I can see it is not constrained where it comes in contact with the house (there are pieces of 1/2" plywood that are against the wall where the slab meets the house) I want to pour a floor with an integrated footer for the wall and put the new block on top of the footer to support the slab. underneath the slab currently is dirt, and there is an existing footer for the wall, but I do not believe that it is in very good shape. I was looking at jacking up the slab just enough to take the weight off of the outer wall so it can be removed. I was also considering supporting the slab with three 8 foot wooden beams spaced along the length of the slab 2 feet from each end, and one beam in the middle. This may be a better way to support the wall than my previous plan?