I just finished helping a colleague clean out his (large) garage at his new house. He's gradually converting it to a indoor gym for himself and his kids (ie: indoor swing set, toys, etc, with a small corner for his weights). The previous owners used the garage for parking their cars, so the floor is a real mess: oil spills, random dirt and other spills, he himself spilled beer and food a few times on it.

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We need to clean the floor and make it look presentable, but there's a catch: certain items (bench, wooden play fortress, etc) have already been assembled and bolted into the concrete with anchors. Those areas were already clean, so no worries there, but this means we can't just buy a heavy duty solvent and use a pressure washer afterwards to blast it all out. We're going to have to just mop and scrub.

That being said, is there a particular general purpose cleaner we should use?

  • It sounds like the acid-based cleaners wouldn't be a good idea, since they can leave a white film behind and damage the concrete if we don't spray it away with a hose afterwards.
  • The concrete also seems to have a waxy finish on it, so I don't want to damage it if it servers an important purpose, so a number of alkaline abrasives also wouldn't necessarily be a good idea.
  • We'd considered simple floor cleaner like what one would use on a tile floor, but it doesn't seem to put a dent in the grease/oil stains, and even when diluted, seems to leave a sticky residue behind that takes days to go away. Maybe since the floor is cold, it doesn't evaporate away very quickly.
  • We need to use something non-toxic. Kids will be touching the concrete, and we don't want them getting sick if they don't wash their hands before having a snack.

Interesting point: while doing some woodworking, he spilled a lot of carpenters glue on the floor, and when it dried, it easily came off with a paint scraper. The concrete looks very clean, and still has its waxy surface, so there must be a cleaner that can do this if cheap glue can.

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Is there some kind of general purpose cleaner I can use to mop the floor with periodically and gradually get out the grease, oil, and other stains. If we have to mop the floor 10 times, that's fine, since he's a bit of a neat freak, and would likely be mopping up footprints from shoes every couple of weeks anyway.

Thank you.

  • is there a strong reason to keep the concrete exposed? Besides the hassle of trying to keep unsealed concrete clean, I'd be more worried about all the play elements in there. Bonking a head on bare concrete isn't fun. I'd suggest just putting new flooring on top...such as the foam gym floor tiles.
    – DA01
    Jan 27, 2016 at 20:12
  • The play area is cordoned off, so I'm not worry about kids hitting their heads on the exposed concrete. We can't really take down the stuff that's anchored down without tearing it apart. If I can just get it clean enough now, then I can just mop it with water and a pinch of normal floor cleaner in the future.
    – Cloud
    Jan 27, 2016 at 21:04

1 Answer 1


Use a solvent degreaser for concrete floors, following manufacturer's instructions, on the oily areas. Then mop with warm water mixed with a bit of liquid laundry detergent and let it dry.

If the treated area looks different due to alteration of the "waxy finish", use a hard floor wax remover on the entire floor, again follow instructions.

If you wish to restore the "waxy finish", apply a coat of hard floor wax finish. The cost of all the supplies needed should be less than $35.

  • Thank you for this. I had considered CLR, but then I read on their site that using it on grease/oil just makes it worse, and harder to clear the entire floor. The reality is that I need to de-grease just the oil spots, and then wash the rest of the floor with a different chemical. Lesson learned :)
    – Cloud
    Jan 28, 2016 at 15:35
  • One other thing: what would you recommend washing it with on a weekly basis, after having restored the "waxy finish"? Would a normal pine-sol or Mr. Clean floor cleaner be suitable, or would it just wear away the finish again? Thanks!
    – Cloud
    Jan 28, 2016 at 15:36

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