The basement area below our kitchen was turned into a workshop space. Before I used it as a workshop, I needed to finish the floor. After researching various finishes, I decided to use an epoxy coating with a grit additive — this coating will prevent oils, paints, and other substances from penetrating or staining the concrete. The grit additive in the epoxy coating adds traction when the floor is wet — otherwise, it would be almost as slippery as wet ice.
The first step is to prepare the floor for the epoxy coating. I protected the trim on the walls with blue painter’s tape. I also thoroughly washed the floor, first with a standard detergent and then with a mild acid solution to remove any stains. I originally thought that the acid might etch the surface of the concrete enough to rough it up so that the epoxy would adhere well, but this didn’t work out.
I ended up grinding the floor. Commercial floor grinders would make short work of this ~300 square foot space, however, the rental would have cost several hundred dollars and I’d also need to rent a truck and get someone to help me load and unload the incredibly heavy grinder.
Instead, I purchased a 7″ angle grinder and a 16 grit grinding wheel. I purchased and set up a cyclonic dust collector and a dust collecting shroud on the angle grinder. It took about six hours to grind the entire floor down — about two hours longer than it would have taken to rent a truck, transport a rental grinder, and grind the floor with a commercial grinder. However, it cost far less to buy a used angle grinder, wheel, and dust collection system, and I now have tools that I can use to cut and grind concrete, as well as a basic, simple dust collection setup for my workshop.
Applying epoxy is a bit different than painting (and if you are in New England and need epoxy, the folks at New England Epoxy Supply are incredibly helpful and knowledgable). The epoxy is much thicker, and it’s harder to spread on the floor than paint. Also, epoxy comes in two bottles — one has resin, and the other has hardener. Once the two bottles are mixed, the epoxy starts to harden quickly. Depending on the epoxy, you might have only 10 minutes before it completely solidifies. The epoxy I used had 45 minutes of “pot life” — that is, I had 45 minutes after mixing it to apply it before it would be too hard to use. So, I had to work quickly and didn’t take any pictures of the application process. It also gets on EVERYTHING! I wore special shoes that have long spikes on them so that I could walk across the coated area, if necessary, and avoid tracking too much epoxy around. And, the epoxy needs to be cleaned off any tools before it hardens — so it needs to be applied, and then the tools need to be cleaned, AND any spills or messes cleaned up within that 45 minute window.
I mixed up the epoxy, added gray pigment (otherwise the epoxy would be clear), and spread it onto the floor with a roller. I had barely enough for the entire floor — epoxy is expensive, so you don’t want to buy or mix more than you’ll need.
After the base coat of epoxy cures for 12 hours, it’s ready for a top coat. I mixed up this second layer of epoxy, added a grit additive, and again had about 45 minutes to apply it. This top coat needs to be applied in the 12-24 hour window after applying the base coat so that it will adhere properly.
Now, the workshop floor is durable, and oil, paint, and any other goop that gets on it is easy to clean and remove.