Concrete – How to repair and level the settled edges of a basement slab

I had something similar in my basement - a drain in the middle of the floor, and the floor around it sloped toward the drain.

We did pretty much what you described and it turned out really well

1. Clean the floor up nice.
2. Used a wire brush to roughen up the surface a bit so the new concrete will adhere well.
3. Poured in regular concrete to almost level it out.
4. Used thin-set mortar to finish it off (the same mortar you would use for setting tiles)

As for your sagging beam - they make special house jacks for that kind of stuff, but a hydraulic car jack with a 4x4 would probably do the trick as well (for your situation anyways).

The floor does not have to be perfectly level. Just flat enough so the flooring lays flat. I use a 4' level or 2x4 and check the area. You dont want the level to teader or have a gap under it more than 1/4"-3/8". Small trouble areas you can fix with doubling up on the underlayment.

If you need to level the floor more use floor leveler let it set up then drag drainage grooves towards the drain. Using a screwdriver will be the best width. Thicker would be better but it will mess up the surrounding concrete. You will want to remove the old floor drain set it at the height you want the new concrete to be. Once the concrete sets up you can drill or cut some notches where you put the drain grooves. Doing it any other way may cause you to fill your drain with concrete.

You can also cut drainage grooves once the concrete has dried. I would use a circular saw or grinder with a mason blade. But this will not leave a thick groove and trying to make it wider would be time consuming. If you were to do this i would would suggest cutting 2 lines about 1/2- 1" apart. then take a chisel and break out the area in between.