All natural removalIf your spill is fresh, apply a liberal amount of cat litter onto the affected area of your concrete driveway and use a nylon-bristled brush to spread it evenly. Allow the litter to sit for at least one hour to absorb the spill. After the oil has completely absorbed into the litter, use a broom to sweep up the mess. You can also use a baking soda or dishwashing detergent bath to remove the stain. First, lightly wet the area with water and sprinkle a hefty amount of baking soda or dishwashing detergent and let it sit while you boil a large pot of water. When the water is boiling, pour it over the area and scrub with a stiff-bristled brush. When finished, rinse off the excess soap and repeat as necessary to achieve the desired results.
- Avoid using metal-bristled brushes on your concrete driveway; they can damage the surface, and if bristles get stuck in the driveway they can cause rust stains.
- Keep a bag of litter or baking soda in the garage in case of a spill.
Pressure washersUsing a medium- to heavy-duty pressure washer can remove or lighten oil stains on your concrete driveway if the spill is relatively new. First, apply a commercial-grade cleaner to the oil stain and scrub with a brush or broom. Then add detergent to your pressure washer and begin spraying. Move at an even pace and keep the nozzle at the same distance from the surface of the concrete at all times to ensure that no streaking occurs. Allow the detergent to sit on the spot for five to ten minutes before rinsing for best results.
- Don’t add bleach to your pressure washer; it can damage some of the parts.
Chemical removersA more aggressive method for removing larger stains on your concrete driveway involve a commercial concrete degreaser. These degreasers are a concentrated alkaline soap that loosens the oil from the concrete to permit easier removal. The problem with these products, however, is that they don’t work well on large spills or spills that have been sitting for a long period of time. Poultice is also an effective treatment for smaller stubborn stains. A poultice is a mixture of an absorbent material like cat litter and a strong solvent such as acetone that is smeared atop the stain. The mixture is then covered with plastic while the material sucks the stain out of the concrete.
- Wear protective clothing and eyewear when working with chemicals.
- Keep small children and pets away from the area and keep the number to poison control handy in case any accidents occur.
- For older stains, try using a TSP (trisodium phospate) or paint thinner such as turpentine.