How to Remove Stubborn Oil Stains from a Garage Floor

Garage floors take a beating, but few things look as unsightly or feel as neglected as a sprawling, dark oil stain. Beyond the aesthetics, trapped oil can deteriorate concrete over time, leading to pitting and permanent damage. Getting a floor truly clean requires more than just a quick sweep and a splash of water. It demands a chemical process to break down the carbon bonds of the oil, followed by mechanical agitation. When done well, the concrete returns to its natural gray state, free of both the slick residue and the deep-seated discoloration.

1. Strip the Space First. Remove all vehicles, storage bins, and loose debris from the garage. Sweep the entire floor thoroughly to ensure you are treating the stain, not the dirt layered on top of it.
2. Soak Up the Mess. If the oil is fresh, pour a generous layer of non-clumping clay cat litter or sawdust over the puddle. Press it down with your boot and let it sit for at least four hours to pull the liquid out of the concrete pores.
3. Deploy the Degreaser. Generously apply a high-alkaline concrete degreaser directly to the stained area. Use a spray bottle for controlled application or a stiff brush to work the liquid into the concrete.
4. Scrub Deep. Using a stiff-bristled nylon or wire brush, scrub the degreaser into the stain using a circular motion. Apply firm pressure to ensure the cleaner penetrates deep into the concrete surface.
5. Let Chemistry Work. Let the degreaser sit for 15 to 20 minutes, but do not let it dry out. If it starts to evaporate, mist it lightly with water to keep it active.
6. Flush and Finish. Rinse the area thoroughly with a high-pressure hose or pressure washer. If a shadow of the stain remains, repeat the degreasing process until the concrete looks uniform.