How to Clean Grease and Oil Stains From Your Concrete

An unblemished concrete patio, driveway, or walkway can feel like a magnet for leaking vehicles and spilled oil, which will penetrate the porous surface of a concrete and leave a lasting stain. That is, if you let it. There are a few ways to tackle oil stains on concrete to restore them to like-new condition.

Clean up oil stains fast

The sooner you get to an oil stain, the better it is for your chances at stain removal. Using an absorbent material like cat litter, saw dust, or a chemical absorbent for use in shops and garages is a good first step. While cat litter and saw dust are okay to use on cooking oil, the chemical type of absorbent that works well on motor oil or other greasy liquids can cause heat during the absorption process that could cause a fire when mixed with organic oils, turpentine, or cleaning products that contain hydrofluoric acid. Even if you don’t get to the spill right away, using an absorbent as a first step is a good idea.

Some common tools you’ll want for cleaning up oil stains:

Use a homemade cleanser

If you don’t have immediate access to some kind of absorbent material right away, you can try using a homemade cleanser. First, sop up as much of the oil as you can with rags, newspaper, or paper towels to make sure your cleanser penetrates as deeply into the concrete as possible. Then, use a stiff bristle scrub brush to scour the affected area with a 50/50 solution of vinegar and water, a mixture of two tablespoons of baking soda to one cup of hot water, or a mixture of one teaspoon of dish detergent to one cup of water. Don’t use these in combination with each other, as they can cause a chemical reaction that will stop them from being effective at breaking down the stain.

Use a pressure washer

Another common method to remove a recent oil stain is a power washer with detergent in it. Using hot water will improve its effectiveness. Before spraying an area with the washing wand, make sure to wipe up as much of the oil from the surface of the concrete as possible so that you don’t spread the oil to adjacent surfaces. Adding a degreaser to the spill before you wash it and allowing it to soak into the surface for about fifteen minutes will help the detergent penetrate the surface of the concrete and remove more of the stain. Also, be careful to choose the appropriate pressure setting on the power washer to avoid damage to the concrete or nearby objects. Make sure to clear away anything that might be broken or cause damage if a strong stream of water hits it.

Make a solvent paste

If initial stain first aid doesn’t work, there are a few more steps to take before you give up. The next step is to try using a poultice. The poultice can be made from a solvent like acetone, mineral spirits, or an oil stain remover combined with cat litter, saw dust, diatomaceous earth, or a clay oil absorbent made for shops and garages. Mix your absorbent and solvent together to make a paste, making sure that you have proper ventilation, especially if you’re using acetone. Then, spread the paste onto the stain, covering past the border of the stain by about an inch and leaving a layer about a half inch thick. Once that’s done, use painter’s plastic, cling wrap, or poly film sheeting to cover the paste and tape the edges all the way around with painter’s tape so that the liquid solvent won’t evaporate. Then leave the poultice on for 24 hours to let it seep into the concrete before scraping the paste off with a squeegee or plastic putty knife. Then you can use a stiff bristle scrub brush to remove the rest of the paste and rinse the area with water. You can repeat this process a few times if the stain is particularly stubborn.