I am laying some laminate flooring in my basement and after I ripped up the carpet I found a rather large bump on the concrete subfloor. I need to flatten this thing out so I can lay laminate on top of it.

Note that I am not trying to level the floor - I'm just trying to make it have no bumps.

What's the best way to remove this concrete bump? Should I chisel it out?

Tried to upload a picture, but imgur keeps rejecting it (yes, it's under the size limit, by a lot). I'll try again later. Just imagine a concrete floor with a little acne.

  • I have this same problem. Installing new flooring and there is a very noticeable hump in the concrete. I imagine the only solution is to hammer it down below level with a handheld jack hammer or air hammer and then fill it in flat with some type of portland cement.
    – Preston S
    Commented Feb 28, 2017 at 21:48
  • Do you have a large grinder you could fit a diamond cup wheel to?
    – brhans
    Commented Feb 28, 2017 at 22:13
  • @brhans I do not have a grinder. I have rotary and oscillatory dremels, however.
    – rothloup
    Commented Feb 28, 2017 at 22:15
  • Weeell ... a decent grinder with a 7" wheel could level out some bumps in minutes. A dremel ... well how many hours do you want to spend on it and how many times do you want to replace the teeny tiny grinding disc/wheel/thingy?
    – brhans
    Commented Feb 28, 2017 at 22:19
  • 1
    Get a cold chisel for concrete and heavy hammer to drive it. Or get one of those 5 or 6 ft steel bars. All seem have a spade or chisel on one end, but on the other end some have a point and others have an earth tamper. I'd think you want the point. Commented Feb 28, 2017 at 23:59

2 Answers 2


A silicon carbide rubbing block. I'd swear this is a duplicate but it's not showing up in the "related" links.

rubbing brick

Inexpensive hand tool, makes short work of bumps, by hand. Use some water to lubricate and prevent dust while grinding.

  • Not what I used in this particular case, but this answer seems more "right" than my solution.
    – rothloup
    Commented Mar 1, 2017 at 3:27
  • They work pretty well, and yet I managed to get through a number of decades before I found out about them. I suppose I must have walked past them quite a few times, but I never "saw" them as I would have had no idea what they were for...
    – Ecnerwal
    Commented Mar 1, 2017 at 3:47

In this particular case, I was able to use a cold chisel and a hammer, as @Jim Stewart suggested, to chisel it out. It was a pretty small patch and it didn't take long at all.

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