Any tips on preping a concrete floor to stain?

I have a very smooth 30 year old concrete basement floor that I want to stain with a water based stain. The floor is bare concrete with no paint or sealer, just some spots where I dropped dry wall mud on the floor. I have a friend who finishes wood floors and he has offered to use his floor buffer to prep the floor. He has never used the buffer on concrete so we have no experience whatsoever. I planned on washing the floors before we started with TSP and again after. I have seen videos of people using a buffer and wetting the floor to eliminate the dust and wet vacuuming the slurry. I have been told to use an 80 grit screen with a pad to achieve the feel of about 120 grit paper on the floor. Is that about right? There are two rooms; one is 18’x13’ 5’ and the other is 16’ x 10’. How many screens can we expect to go through? Is there a high risk of being electrocuted using an electric sander over a wet surface? Should we wear rubber boots and gloves? I’ve read a ton of articles on doing it and they are similar but there doesn’t seem to be a consitant set of steps to follow. Can anyone provide a list of steps or give me some tips before we dive into this blindly? Thanks! Marco

I have never stained concrete myself, Marco, but several forum members have done that. So I'd suggest that you use the "search" feature on the forum for something like "stained concrete floor", and see if you can find out who did that, and how. And if necessary, you could PM them for more details / questions. Then I'd also suggest that you make a thread documenting how YOU do it, with notes and photos, so I can make that into a "sticky", and link it from the FAQ, for future reference!!! :) :!: :yahoo: :thu: - Stuart -

I actually found this forum by searching “Concrete floors in a music studio”. I found quite a few posts on the topic here but no “step by step”. I will do my best to document my floor but it may end up being “How not to stain concrete”. Thanks!

Hey Marco, You have the proper steps indicated. A 60 grit sand screen would be better. It will open the concrete up a little more with out leaving to heavy of scratches. But the scratches are you friend for the bond line. The most important thing you need to do is open the surface (sand it), make sure it is dust and cleaner residual free before applying your stain. ( final rinse with clean water, let dry overnight) What material do you propose to use? There are quite a few out there and they perform differently. Some are integral with sealer and some need a sealer. My favorite is a acetone based dye with a water based epoxy finish. The dye penetrates better than most. I would avoid acid based stains, as they are more difficult to apply. And result in more failures. Hope this helped T

TomVan wrote:

Hey Marco, You have the proper steps indicated. A 60 grit sand screen would be better. It will open the concrete up a little more with out leaving to heavy of scratches. But the scratches are you friend for the bond line. The most important thing you need to do is open the surface (sand it), make sure it is dust and cleaner residual free before applying your stain. ( final rinse with clean water, let dry overnight) What material do you propose to use? There are quite a few out there and they perform differently. Some are integral with sealer and some need a sealer. My favorite is a acetone based dye with a water based epoxy finish. The dye penetrates better than most. I would avoid acid based stains, as they are more difficult to apply. And result in more failures. Hope this helped T

Hi Tom, thanks for your reply! We got the sanding part down this weekend and it went well. I didn't see your post but after we burned through the first 80 grit screen, we realized a 60 would be better and went back to Home Depot to get more. It took 12 screen total! We got better results by using plenty of water and TSP made a big difference too (I forgot the TSP on the first screen). Now that the floors are clean, they look like they will have some cool patterns when it's all done. The stain I'm going to use is H&C water based stain and will seal with H&C Wet Look Sealant. The reviews on the product are very mixed leaning on not so good... but I get the impression that the bad reviews were due to the floors not being prepped properly. I’m fairly artistic and was a painter for many years so I will try to apply some creativity when I put the stain on. I’ll post some pics shortly…

Marco - Warren Jergen sound put in stained concrete floors in his studio in Kansas. http://www.johnlsayers.com/Pages/jergen.htm You might try to contact him. He used a concrete cutter to cut out the tile pattern before staining.

Thanks for the reply John! His floors look great too. I'm getting closer.. Here my friend is using the 80 grit screen on the floor. The lower walls are taped with plastic to protect them from the cleaning and the following steps. This is after the second coat of stain. I have a few clean up spots where the stain puddled and then I'll clear coat.