Concrete – How to level this concrete floor so I can install laminate

If the gashes you describe are not large, say more than 1/4 inch deep or more than say 6inX6in in size, don't worry about them. go right over them. If you really feel that they need to be filled, use the floor leveler. it does contains silicates which is only harmful in a dry dust state, and then only if you live in the stuff for a long long time. Once it is wetted/mixed and on the floor , there is no danger if you don't go crazy sanding it. You can also use regular drywall compound or quick set if you have the patience to wait for it to dry before starting your floor.

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.