How to Epoxy a Garage Floor

Sika lists these supplies for its kit. Add degreaser, crack filler, painter's tape, and a stopwatch or phone timer.

• Epoxy kits, resin and hardener. See the table below for the count.
• Moisture meter or an 18 × 18 in plastic sheet and duct tape.
• Thermometer for the slab and the air.
• Floor grinder or sander, plus a vacuum. Rental usually runs $100 to $200 a day.
• Mixing drill with a paddle. Sika says not to mix by hand with a stir stick.
• Paint brush for the edges and a 5 mm lint-free roller with an extension pole.
• Mask, gloves, and safety glasses. Check the safety sheet for your kit, since some products call for a respirator.

Kit counts depend on the coverage printed on your label. This table uses 200 sq ft per kit per coat, 2 coats, and 10% extra. For a 400 sq ft garage that is 400 × 2 × 1.1 ÷ 200 = 4.4, so buy 5 kits. Enter your own label coverage in the epoxy floor coverage calculator.

Rough or porous concrete soaks up more on the first coat. For a flake floor, add the chips with the epoxy flake calculator.

Based on the Sikafloor-200 kit at 68°F. A damp slab or a failed test stops the schedule at Day 2.

• Slab age: Sika prefers a new slab to cure for at least 90 days before coating.
• Moisture: tape an 18 × 18 in plastic sheet to the concrete and wait at least 24 hours. Condensation or darker concrete means it is too wet to coat. A meter reading should be 4% or less for this kit.
• Weather: stay between 50°F and 86°F with humidity no higher than 80%. Outside that range you risk wet spots and poor adhesion.
• Old coatings: test adhesion and compatibility first. Anything loose has to come off, and the rest needs sanding until no gloss remains.
• A slab that fails has to be solved before you buy a kit. The basement epoxy floor cost guide covers moisture testing and vapor barriers in more depth.

Sweep and vacuum, then treat every oil and grease stain with a concrete degreaser. Do this before you grind, because sanding spreads the oil across the floor. Oil left in the concrete causes poor adhesion, black spots, and wet, uncured patches. If you rinse with water, let the slab dry fully before moving on.

The surface needs an open profile. Sika specifies ICRI CSP 3, which feels like fine sandpaper, and warns that smooth concrete can lead to peeling later. Its kit calls for mechanical prep with a sander or grinder, which you can usually rent.

• Some budget kits allow acid etching instead. Follow your label, but grinding gives a more reliable surface and removes old sealers that acid will not.
• Drop water on the ground slab. If it beads, a sealer or smooth patch is still there.
• Pay attention to the edges, since a floor grinder will not reach them. Use a hand grinder or sander.
• Wear a dust-rated mask and use a vacuum shroud. Concrete dust is harmful to breathe.

Fill cracks and holes with a crack filler made for concrete. Once it has cured, sand it level with the slab, then sweep and vacuum everything again. Any dust left behind ends up in the coating. A crack that keeps moving will likely show through later, so expect some repairs to be cosmetic.

• Mix only once the prep is finished and the moisture result is acceptable.
• Split the floor into sections, one per kit, and mark them with tape or chalk at the walls. This keeps each kit spread to the right thickness.
• Never mix two kits at once. Sika warns that the working time is limited.
• Coat as the day cools and out of direct sun. Sika warns that rising temperature makes concrete off-gas, which causes bubbles and pinholes.
• Tape the line at the garage door if the slab runs past it, and pull the tape after about 45 minutes, before the coating sets.
• Plan your exit. Start in the far corner and finish at the door.

Stir each part on its own first so it is uniform. Add the hardener to the resin at the ratio on your label, then mix with a drill and paddle for the time the label gives. Start coating right away. Mixed epoxy heats up faster in a pail than on the floor: Sika's kit starts to gel after 30 minutes in the pail, against about 45 minutes of working time on the floor at 77°F.

• Brush a band of coating along the walls in the far corner.
• Pour a 1 to 2 in wide ribbon along the back of the section.
• Spread it with the roller to the label thickness. This kit targets 8 mils, or about 200 sq ft per kit.
• Back-roll with light pressure to remove puddles, ridges, and roller marks.
• Keep a wet edge. If the next batch comes too late, the overlap can show in the finished floor.
• Check your spread rate as you go. Our epoxy floor thickness guide shows how to convert wet film to dry film.

Flake goes into the wet coat, so have it ready before you start rolling. Throw it upward and let it fall evenly. A full broadcast keeps going until the wet coat cannot hold any more. A partial broadcast leaves the base color showing. A full broadcast needs scraping smooth once cured, and a clear topcoat over the chips. Use the epoxy flake calculator to work out the pounds and boxes.

Roll the second coat the same way, inside the recoat window on your label. If you miss it, the surface has to be sanded until the gloss is gone and vacuumed clean before you continue. Temperature moves the window, as this table from Sika's sheet shows.

Sikafloor-200 Garage Epoxy Kit. Measure the slab, not just the air. Concrete stays cold well after the air warms up.

• Keep water, damp, and condensation off the floor for at least 72 hours, or it can show white stains or lose its gloss.
• Do not drive on it early. Give it the full vehicle time on your label, and longer in a cold garage.
• Wait for the full cure before you clean with chemicals or leave oil spills on it.
• Clean tools straight away with the solvent your sheet names. Cured epoxy can only be removed mechanically.

Materials for a 400 sq ft garage run about $200 – $1,080. A professional epoxy floor runs $1,600 – $4,000, and most of that labor goes into prep. Bob Vila's advice is that applying epoxy is the easy part and preparing the floor is the hard part.

• Do it yourself if the slab is dry, sound, and uncoated, and you can keep the garage empty for about a week.
• Hire a pro if the slab fails a moisture test, has an old coating, or needs major repairs. Check a quote against the epoxy garage floor cost calculator.
• Compare finishes first. Polyaspartic vs epoxy explains why polyaspartic is a harder DIY job, and the epoxy floor pros and cons cover what can go wrong.

Steps, limits, and timing follow Sika's instruction sheet for one DIY kit, used as a worked example. We publish planning tools and have not tested this product. Other kits differ, sometimes a lot, so follow your own product's instructions and safety sheet.

• Sika: Sikafloor-200 Garage Epoxy Kit instruction sheet (manufacturer)
• Carboline: Coating Concrete, Part 2 (coatings manufacturer)
• Bob Vila: Epoxy Garage Floor Cost (updated Apr 26, 2024)
• Concrete Network: What's the Best Concrete Garage Floor Coating?