How To Stain Concrete

Q. Can a Previously Carpeted Concrete Floor be Stained?

A. The short answer is yes, but there are a few things you need to be aware of and a few remedies to the issues you may face.

1. Your carpet may have been held down by tack strips which when you remove them will leave small holes in the concrete all the way around the perimeter of the room.
2. Your carpet was held down with glue. Now this may be glue all over and completely covering the flor or it may just be little squiggles of concrete all over the floor. The latter occurs sometimes in conjunction with the tack strip installation, ” just great two problems to deal with” is probably what your thinking right now.

Never fear I have some quick and easy solutions to both these issues. Lets first address the situation of the tack strips because this seems to be the installation of carpet that most folks have.

Removing the tack strips is not that hard as you can use just the claw end of a hammer but you may want to use a flat sided nail puller also. A hammer that has a straight claw is easier to use for this application as you can use another hammer to tap it under the tack strips and then just gently pry it up.

When all of the tack strips have been taken up you will find that you will probably have small holes all the way around the room. This perfectly normal, the next step is to brush out the holes and make sure they are clean and dry.

You will need to purchase a bucket of Anchoring Cement (hydraulic cement) and a bottle of bonding agent. Now you will need to dilute the bonding agent 1 to 1 with water, then use a small brush and coat the holes with the bonding agent and let the bonding agent dry. This diluted solution will penetrate into the pores of the concrete better than just applying the bonding agent straight.

After the bonding agent has dried mix the anchoring cement to a pancake batter consistency and  apply another coat of bonding agent to the hole and fill with the anchoring cement. Use a trowel or plastic putty knife to scrape off the top to make it flush with the concrete.

The next day use a drywall sandscreen to “sand” the surface and smooth it off. These “repaired” areas probably will not stain exactly the same as the rest of your floor. You can use acrylic paints to faux paint the spots later. That is another lesson we will touch on in another post.

This may be against what you may have already read about putting in the bonding agent. Some say put in the bonding agent and then immediately fill the holes with the anchoring cement. Over the past decade of experimenting with this procedure we have found that diluting the bonding agent and then applying a second coat before filling the holes with anchoring cement works better in keeping the cement in the holes long term. In fact our concrete staining business has never had a call back indicating that the fill material has ever come out.

Next let’s move on the address the glue on the floor if there is any. There are several products on the market that can do a very good job in removing glue such as Glu-Gon and Bean-e-doo. After using either of these products to remove the glue from your floor it is recommended that you scrub the floor with a buffer (floor maintainer) and black pad. It would also be advisable to use a sandscreen under the black pad as an extra measure to ensure that all the glue has been removed from the floor and will not act as a “resist” to the stain that you are planning to apply.