Staining old concrete floors can be done with the right knowledge about the concrete floor and with hard work prepping the concrete. We have stained an old concrete floor that was poured in the 1920’s and the floor came out amazing.
If you are planning on acid staining an old concrete floor that has been poured a long time ago, the first thing that should be done is to test the concretes porosity. Sprinkle a few drops of water and check to see if the water is soaking into the concrete (the concrete will appear darker and the water wont beed).
If the water soaks into the concrete, the next step would be to see if the concrete will accept an acid stain. In an area that wont be visible apply a small amount of the acid stain to the concrete and wait a few hours. If the concrete is not changing colors or the color is very faint, the concrete might be lacking the necessary lime for an acid stain to work. The next best thing to stain concrete, with out worrying about the lime content in the concrete is an acetone dye or water based stain.
The only main thing you have to worry about when using an acetone dye or water based stain when staining an old concrete floor is that the concrete is able to soak the dye in and that the concrete is free from any paint, oil, glue, or any thing else that might prohibit the penetration of the dye. These stains will give a look vary similar to an acid stain.