How to Prep a Garage Floor and Apply Epoxy

An empty garage with half painted floors.

California Harts / Flickr / CC By-SA 2.0

The standard for a tough, good-looking surface on the garage floor is garage floor epoxy. Although it is common to hear people refer to “epoxy paint,” in reality, epoxy and paint are different products with different chemical compositions. Epoxy creates a tougher coating than paint, but it is a little trickier to apply. Careful prep and an organized approach are the keys to success. Application of garage floor epoxy can vary a little from product to product, so be sure to check the instructions on the product you choose.

Tools and Supplies You Will Need

Epoxy garage floor coating is commonly sold in kits that include the two-part epoxy, etching solution, and decorative color chips (which are optional) as well as complete instructions. Some kits also include an instructional DVD. Color choice is very limited, as many coatings are simply gray, while some are brown or off-white. Check the contents of the kit so you know which additional supplies are required.

  • Broom
  • Wet-dry shop vacuum
  • Concrete degreaser
  • Stiff brush
  • Garden hose
  • Epoxy floor coating kit
  • Safety gear
  • Painter's tape
  • Plastic sheeting (optional)
  • 3-inch paintbrush
  • 9-inch paint roller with 1/2-inch-nap roller cover

Instructions

Clean and Degrease the Floor

Use a broom and wet-dry vacuum to clean debris from the floor. Remove grease with a degreaser and a stiff brush. Rinse the degreaser with a garden hose and allow the floor to dry.

Etch the Concrete

Etch the concrete floor using the etching solution provided in the epoxy coating kit, following the manufacturer's directions. Wear all recommended safety gear. Mix the etching solution with water, as directed. Pour the solution onto the floor and work it in with a stiff brush or broom. It will foam and fizz, which tells you it is doing its job to abrade the surface. Rinse the entire area thoroughly with a garden hose. Let the concrete dry completely, which may take several days.

Prepare the Room

Apply some wide painter’s tape along the bottoms of the walls. You may also want to tape some plastic sheeting to the bottom foot or two of walls. If it’s not too difficult, consider removing any baseboard, which would allow you to roll epoxy right next to the wall and eliminate the need to cut in the edges with a brush.

Mix the Garage Floor Epoxy

A two-part epoxy consists of a catalyst (or hardener) and a resin (the paint), which must be mixed just before application. Stir the paint a bit, then begin pouring the catalyst in while continuing to stir. Once the catalyst container has been emptied, stir for another two or three minutes until the two parts are thoroughly mixed.

Put the lid back on the mixture and let it rest for the amount of time specified by the manufacturer, which will vary depending on the temperature. If you are using decorative color chips, do not add them to the mix.

Apply the Garage Floor Epoxy

Start applying the coating as soon as the epoxy mix is ready. You will have no more than two hours to apply the epoxy and even less time in hot weather. Keep the garage well-ventilated throughout the application and initial curing.

Use a 3-inch paintbrush to cut in along the edges, then use a 9-inch roller with a 1/2-inch-nap roller cover (with an extension handle) to spread epoxy on the floor. Work in 10-by-10-foot sections. This work will go quicker if you have a helper handling the cut-in work. Maintain a wet edge by rolling over the edges of previously applied epoxy, and be sure to roll an even coating.

If you are using decorative color chips, apply them by hand over each section after you’ve spread the epoxy. Take a small number of chips in your hand and toss them up and out onto the floor. Again, a helper can speed this process up. For the second coat, wait at least 12 hours before application.

Let the Garage Floor Dry

Don’t start walking on the new epoxy surface for at least 24 hours, and plan to wait at least several more days (and preferably a week) before pulling the car back into the garage.