I have an area of concrete slab in a hallway measuring 5'x7' which I want to even out and need to remove about 1.25" from.

This is an area being lived in so am hoping for the cleanest possible solution.

I've been reading about some pretty advanced concrete grinders that advertise as being 'dust-free', ie. removing the majority of the dust on their own. Sounds promising but I don't know if they can take of 1.25"?

Does anyone have thoughts on the best way of removing that much concrete from a slab?

  • 2
    Sounds like way too much to grind. Cut the perimeter out with a saw, chisel or jackhammer out the area, re-pour at your lower height. It will not be clean. – Shimon Rura Jan 7 '17 at 5:00
  • ... presuming that there aren't rock outcrops or boulders which extend to just under the current slab. And that there aren't water table issues. Sometimes there are good reasons the basement didn't go any deeper. (I'd love tomorrow the later-poured floor in the older part of my basement, but I'm terrified of what might be under it givenits irregularities, and nervous about anything that might disturb the brick-over-fjeldstone foundation.) – keshlam Jan 7 '17 at 5:22

Generally you'll not be able to remove 30mm from a concrete slab without cracking up the remainder. In the UK a typical slab might only be 100mm thick.

However (in the UK at least) it's unlikely you're looking at the floor slab, but rather the floor screed (sharp sand and cement 3:1) used to finish off the floor. The 100mm concrete floor slab is actually a sub-floor slab underneath the finish screed.

Now, the floor screed can be hard, but it's laid fairly dry and is often not too difficult to chop out. Typical thickness ranges from 50mm to 75mm (but can be as little as 25mm...)

Starting in a corner, try chopping a small exploratory hole with a sharp cold chisel and a club hammer. Check for pipes first, as radiator pipes typically get buried in the screed around the edges of the room.

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