The floor in our kitchen/family room area is polished concrete, the idea having been a somewhat industrial look plus the ability to take punishment. As part of that we had them put two coats of sealant on the floor so anything spilt could just be wiped up. It didn’t work; anything spilt stains the concrete like a sponge, and can’t be got out by any normal means. The kitchen area in particular is now a splodgy-looking mess and noticeably darker than the rest of the same floor.
Any sort of covering such as vinyl or linoleum is out of the question, due to doors and cupboards being so close to the floor. Also we like the look of polished concrete.
We want to avoid having the whole floor ground down and resurfaced, that would render the whole house unusable for far too long - we’d have to move out for the duration. If there was a way if doing this in a fast and dust-free way, that might work though. I imagine it would only have to be taken down a few millimetres, if that were possible; that would have another benefit, which would be to expose more of the gravel in the concrete mix (which seemed to sink down a bit as the concrete dried, and so is hardly visible) - exposed aggregate, I believe it’s called. Ideally it would look something like this http://www.diamondpolishedfloor.com/services4.asp
What we’d like is some sort of process or substance that would suck up the stains from the concrete, to leave it a more or less uniform colour, and then some sort of treatment to stop it happening again. In the latter category we found places like http://www.concrete-floor-coatings.com/ which looks like it might do the trick (although I’m yet to find out whether it’s available here in Australia). But the stumbling block is how to deal with the areas that are now stained and darker, before (presumably permanently) sealing in the end result.
So what I’m asking for is any sort of experience and advice in this area, either from the provider or customer end. Thanks very much to all!
Ive built several homes with acid washed concrete basement floors. I do not have any solutions for you, but perhaps some of this might be helpful.
We have always coated the floor with a urethane type product that is very hard, very durable, and highly stain resistant. We haven’t used it in a high traffic area such as a kitchen but I think it would work fine. It sounds like your contractors used an acrylic sealer for concrete. Such sealers typically are not hard wearing, or particularly stain resistant. I cant think off hand of the name of the product we have used but we always obtained it from the dealer along with the acid stain.
Acid wash is not likely to hide the stains. We have had trouble with contractors dropping drywall mud or other chemicals on our floor before it has been acid washed, and the stains certainly show through.
Because of concrete’s porous nature stains can be difficult to remove. We have used TSP and a pressure washer to some success but I was not really satisfied with that alone. Apparently acid followed by pressure washing can work. An associate that does specialty concrete work stated that there is a product to clean and prep a new floor before an acid wash finish that will remove gypsum, paint and other stains, but I have not tried it.
You would have to strip the existing sealer off first and I am not sure how you would go about this.
I can’t speak to concrete, but I had to clean a badly stained terracotta tiled porch. It was unsealed, open to the elements and badly stained by mold, mildew, tannin from leaves and in some places, moss.
Pressure washing and TSP barely touched it, but 4:1 water:chlorine bleach soak did wonders. I sprayed it on with a garden sprayer.
Indoors, that would need lots of ventilation, but might do the trick. TSP might help with the oily part of kitchen stains.