Perhaps a visitor in an old car (with an oil leak) left you a parting gift in the driveway. Or while you were adding oil to the lawn mower, it was you who made that puddle on the garage floor. Whatever the source, you will one day need to remove a spill or a stain on your driveway or concrete floor made by oil, fuel or transmission fluid.
Stains from these petroleum-based products are particularly ugly to look at, dangerous to slip on and difficult to remove from a concrete driveway. A dirty oil leak from your car makes the worst mess, but even clean oil leaves a nasty stain that can be difficult to scrub away.
Even a heavy-duty pressure washer won't get rid of old oil stains, and if you try to just rinse off a fresh spill and paint your garage floor, you will see that stain again, as oil or gasoline will migrate to the surface and can prevent the paint from bonding. Removing old oil stains can be even tougher. But with a little determination and some time-tested methods, removing oil stains from a concrete or asphalt driveway can be as simple as rounding up a few common household products and a good stiff brush.
Whether you need to tackle a fresh spill or an old oil stain, here’s how you can remove even the toughest oil and fuel stains.
Start With the Spill
With fresh oil spills, the first priority is to contain the fluid and prevent it from soaking in. All concrete is porous, so you don’t want to give the liquid more time to penetrate. The best containment material to soak up spills is clay cat litter. Why kitty litter? Because the clay type is super-absorbent.
If you don’t have a cat, check your kitchen for cornmeal, corn starch or baking soda. If you don’t have those in the cupboard, use sand if you have some - or plain dirt if you don’t. Give your dry material some time to absorb the spill before scooping it up.
Try These Household Product Hacks
Use your garden hose to soak the stain. Water will keep the oil from drying into the concrete while you take inventory of the weapons in your home arsenal. You may be able to get good results using a combination of common household products and hard scrubbing.
There are two basic techniques: breaking up and rinsing away a fresh oil spill...or drawing out and scrubbing away an old oil stain.
Here’s a starting list of materials that you may have handy:
- Baking soda or laundry powder
- Grease-cutting dish soap
- Spray oven cleaner
- Spray lubricant/penetrant
- A stiff brush or broom
Depending on the type of liquid (oil, fuel or transmission fluid) and the age of the stain, you will need to be open to trying a few of these methods - and encountering a few false starts - on the way to your ultimately successful cleaning technique.
Breaking Up a New Spill
If a gasoline or oil stain is new, it may be possible to break it up with a spray lubricant/penetrant, such as WD-40. First, remove the excess oil with cat litter (or baking soda, corn starch or sand). Then spray the entire stain with a generous application, let it stand for 30 minutes and rinse it with the most forceful setting on your garden hose nozzle.
If you don’t have a lubricant/penetrant, try a grease-cutting dish soap. We've all seen the pictures of birds being rescued from an oil spill. This may work just as well in your driveway, as you rinse away a stain with soap or detergent and plenty of water pressure from your garden hose.
If the stain is from transmission fluid rather than oil, spray it with oven cleaner. Then let it sit for 10 minutes, rinse with the water hose and repeat the process as necessary to remove the stain.
Scrubbing Away an Old Stain
If the stain is old, you will need a more forceful strategy: make a paste of baking soda and water. Spread the paste to cover the old stain. Let it sit for 30 minutes and then scrub the stain hard with your stiff brush or broom.
If you don’t have enough baking soda, use powdered laundry detergent. In either case, the secret with this process is to scrub the area with your brush using lots of pressure, while letting the absorbent materials remove the oil for you to rinse away. If necessary, let the paste sit overnight, then scrub again with your brush, rinse with water and repeat until you see clean concrete.
Driveway and Concrete Cleaning Products
If you’ve tried dish soap, laundry detergent and other common household products to remove oil and the stains just won’t give up, it’s time for a trip to the home center or hardware store. There you will find a variety of degreasing products that are specifically formulated to remove oil stains.
- Purple Power Driveway and Concrete Cleaner
- Pour-N-Restore Oil Stain Remover
- Zep Driveway and Concrete Cleaner
- Oil Eater Cleaner and Degreaser
- Goof Off Degreaser
Bear in mind that these cleaners use chemicals to do more of the work, so you can scrub less. Which ones do the best job cleaning oil? You can read user reviews online to get a feel for the results you can expect, and be sure to read all label instructions and warnings, as these products are a step up from household detergent.
New Microbial Cleaners
An interesting alternative to chemical degreasers is the new class of microbial cleaners, which literally eat oil stains. As long as their food source is present, the microorganisms keep eating, producing CO2 as waste. When their food source is gone, the microorganisms die, leaving the stain lighter.
Unlike the chemical cleaners or the paste made of household products, the microbial cleaners require no bucket and brush to scrub - but they do require patience. The method of application is to pour on enough microbial cleaner to cover the oil stain, followed by a light mist of water. Then you let it sit and watch the oil stain fade as the microbes eat the oil. It may take several applications to completely remove oil stains. Microbial cleaners work can remove oil stains from both concrete and asphalt.
If you are interested in microbial cleaners, look for products such as Terminator-HSD and ACT Concrete Cleaner, both of which are sold online.
The Poultice Technique
Contractors sometimes remove oil stains from a concrete driveway by saturating an absorbent material (such as cat litter) with a powerful solvent (such as acetone). This “poultice” is applied to the oil stain and covered to let the solvent break down the oil while the cat litter draws out the stain. Again, this method requires patience, as the absorbent clay in the kitty litter slowly draws out the dissolved oil, lightening the stain.
Caution: Solvents are flammable and must never be inhaled or kept in contact with skin. A safer way to try the poultice technique would be to mix cat litter (or baking soda or corn starch) with grease-cutting dish soap. A consistency like peanut butter will stay in place while the process works.
Or Just Call a Professional
Should stubborn oil stains resist your best efforts…or should you feel that it would be better to delegate the whole subject of oil stains to an experienced professional, there are contractors who specialize in removing oil stains from concrete driveways and floors.
To learn more about removing stains from concrete, visit www.concretenetwork.com. You can search its archived articles on cleaning techniques - or use its locator to find a contractor near you.