How to Remove Oil Stains from Concrete

Concrete is deceptively porous, acting like a sponge for any automotive fluid that drips onto it. When oil settles into the surface, it isn't just sitting on top; it is working its way deep into the capillaries of the slab. Leaving it there doesn't just look bad—it can actually cause the concrete to crumble over time as the oil breaks down the binding paste that holds the aggregate together. Cleaning concrete effectively requires a transition from absorption to chemical emulsification. You need to pull the standing oil out before you ever touch it with water or soap. Once the bulk of the oil is gone, the real work is breaking the bond between the remaining stain and the concrete. If you move too fast, you end up just pushing the oil deeper into the slab, making the dark, unsightly mark permanent.

  1. Soak Up the Oil First. Pour a thick layer of clay-based cat litter or sawdust over any wet oil spot. Let it sit for at least six hours to draw as much liquid as possible out of the concrete pores before sweeping it away.
  2. Deploy Chemical Strength. Spray or pour a concentrated commercial concrete degreaser directly onto the stain. Ensure the product is rated for garage floor use to effectively break down heavy petroleum residues.
  3. Work It In Deep. Use a stiff-bristle nylon brush to scrub the degreaser into the concrete using a circular motion. You need to create a lather that works the cleaner deep into the textured surface of the slab.
  4. Let Chemistry Do the Work. Let the degreaser sit on the stain for 15 to 20 minutes without letting it dry completely. If it starts to look dry, mist it lightly with a spray bottle of water to keep the chemical reaction active.
  5. Flush Away All Residue. Flush the area with a high-pressure hose or a pressure washer set to a wide fan tip. Direct the rinse water toward a drain or onto the lawn, ensuring all the oily residue is washed away from the spot.
  6. Check and Repeat if Needed. Inspect the concrete once it is completely dry. If a shadow of the stain remains, repeat the degreasing and scrubbing process, as deep stains often require multiple passes.