How to paint a concrete floor to look like marble
Before getting into the process, there are two types of paints to choose from for this project: epoxy paint and urethane (sparkle) paint. Both types have pros and cons, but since epoxy paint holds up better against heavy traffic areas (such as hallways), we will focus on that type; be sure to pick up some epoxy paints at your local home improvement store before beginning.
Epoxy paint comes in many colors. However, most do not match the color of real marble. So, if you want to use real stones in your project, this brings us back to urethane paints. Also, note that all of the following steps can be used for even or uneven concrete surfaces.
First, clean the floor with a stiff broom and sweep off any dust. Next, mix up enough epoxy paint to cover about 50 sq feet (5′ x 10′). Stir well by hand for at least 4 minutes, making sure there are no lumps left in the paint before applying it. Use a 2″ paintbrush to apply one coat of epoxy paint, trying to go as slow as possible when brushing since any fast movements may cause air bubbles.
Apply the second coat after 20-25minutes, or a little after the first coat becomes tacky. Each coat should be applied about as thick as a credit card. *The following steps can be replaced with any commercial sealer (from the local hardware store).
Using a good quality commercial concrete sealer, apply ONE coat of sealer, then dry for 24 hours. Next, using a stiff bristle brush, scuff the sealer coat to create a matte finish (do not scratch so hard that you see bare concrete, it should just be enough to get the sheen off). Let dry for 24 hours before lightly sanding with fine-grit sandpaper (220 or higher) or steel wool. Do this step very carefully, making sure not to go too deep; too much stress on the floor will cause it to crumble and break underfoot!
After completing this process, apply at least three more coats of commercial sealer (letting each coat dry for 24 hrs in between), then let cure for seven days. Putting this project on hold at this step will allow the sealer to dry thoroughly.
Next, mix enough epoxy paint to cover about 50 sq feet (5′ x 10′). Stir well by hand for at least 4 minutes, making sure there are no lumps left in the paint before applying it. Using a 2″ roller and working quickly, apply one coat of epoxy paint, trying to go as slow as possible when rolling since any fast movements may cause air bubbles. Let dry overnight or until tack-free.
After allowing for 24 hours of drying time on top of the curing period already completed on your floor (keep all furniture off the floors during this process), gently scuff the marbleized finish with fine-grit sandpaper (220 or higher) or steel wool. Using a 2″ brush, apply one more coat of epoxy paint over the entire surface, making sure to get into all nooks and crannies. Let dry overnight for best results.
After allowing the floor to set for a total of 7+ days, you can begin placing the furniture back on top of your new marble-like floors!