I have a 50' x 6' concrete slab in front of our basement that supports the same size wooden deck above with 6 post for the upstairs. The soil under it washed away due to poor drainage. I have fixed the drainage problem and now need to support the slab.
- slab built into steep sloping bank
- dirt is gone from the outside edge back as far as 3' underneath
- no footing at all
- outer bottom edge of slab is above the ground by 12" for atleast 15' in the center.
How do I add footings to an existing slab. One thought was to form up the bottom of the slab, cut holes and pour concrete in to fill the void. Slab Jack estimate was over $5000
The other choice would be pour pier footings in front of the existing slab and transfer the load.