Cleaning your driveway often requires just one of two tools: a broom or shovel. When it comes to stubborn stains, however, it takes more to get your asphalt or concrete looking great again. If dirt, oil, paint or other stains are present on your driveway, here’s how to get rid of them.
Especially after the wet winter and spring seasons, water runoff, vehicles and numerous other sources can bring mud and dirt onto your driveway where it dries and hardens. The easiest way to clean this off is with a power washer, which you can rent from many hardware or home improvement stores. Otherwise, you can do the job with a stiff-bristle push broom and a garden hose. Start by sweeping away any loose material and then using the hose to soaking caked-on mud for a few minutes before you begin scrubbing with the broom. Depending on how much dirt you need to remove, this can be a large job with a broom. Be sure to use plenty of water.
Decomposing organic matter
Mulch, fallen leaves, pine needles and other organic matter can leave an unsightly brown stain if allowed to sit on concrete driveways. These stains are harmless and temporary, but you can speed their fading with some cleaning.
Begin by sweeping the area, then spray the stains with a garden hose to wash away dirt. Take a large bucket and mix a half cup of liquid dish detergent with three gallons of hot water. A powdered laundry detergent that advertises food stain removal is also effective. Carefully pour the solution onto the stains and work it into the concrete using a stiff-bristle nylon brush. Then, wash off the area with a garden hose. While the surface is still wet, sprinkle powdered laundry detergent onto the stains, and scrub once more. Let the detergent sit for a few minutes before rinsing away. Repeat as necessary.
Automotive oil and solvent spills
Stains from automotive fluids such as motor oil, gasoline and brake fluid are a common source of persistent and unsightly driveway stains. These oils and solvents can also react with asphalt’s petroleum content to soften and deteriorate the material. In any case, it’s best to promptly remove these stains as soon as they appear.
For fresh spills on either asphalt or concrete, begin by soaking up as much of the spill with an absorbent product such as kitty litter. Wait a few hours for the spill to be absorbed, then scoop up the loose material and sweep the area. Use one of the following techniques to remove the rest of the spill.
For stains on asphalt, spray a biodegradable oven cleaning product over the stain (ensure the product specifies “biodegradable” so you don’t wash harmful chemicals into your lawn or storm drain), and wait up to 30 minutes. Just like the baked on grease in your oven, the driveway spill will break down from the cleaner. Then, rinse away the cleaner and stain with a garden hose.
For stains on concrete, you’ll need a different approach to dissolve and draw the stain out of the concrete’s porous surface. To accomplish this, mix a powdered moisture-absorbent product such as corn starch (good for small spills) or diatomaceous earth (good for large spills and available at swimming pool supply stores) into liquid TSP (available at hardware and home improvement stores) to make a thick paste. Spread the paste over a fresh or old stain, and work it in to the surface using a stiff-bristle nylon brush. Apply another thin layer of paste to the surface and wait for it to dry completely.
The TSP should dissolve the oil or solvent, and the absorbing product should bind it. The paste may take from 30 minutes to a couple of hours to work depending on weather conditions. Scrape away the dried paste using a putty knife, and then rinse the area clean with a hose or power washer. Old stains may need multiple applications to remove.
Though less common than other stains, paint and wood stain drips and splatter can be the most visible of driveway stains. The best removal technique depends on the type of stain.
For latex-based paint spills, wet the splatter with water, sprinkling on a household scouring powder and scrub the spill with a stiff-bristle nylon brush before rinsing with a garden hose.
Oil- and acrylic-based paint splatters are more work to erase. On asphalt driveways, the best fix may be to simply recoat the driveway or just the spill area with an asphalt sealer to renew the black surface. This is because the chemicals for removing oil-based paints can damage asphalt. These same chemicals are safe for concrete, however. Pour or brush a paint-stripping product where needed on concrete and work it into the surface using a stiff, natural-bristle brush. Allow it to work for the manufacturer-specified time before rinsing it off. You’ll likely want an environmentally safe, low-VOC stripping agent for this purpose.
While black asphalt driveways don’t show rust stains, the blemishes stick out on the light concrete. Even something as simple as leaving a metal object on the driveway during an overnight storm can produce a rust stain by morning. Muriatic acid (available at most hardware and home improvement stores) is an effective rust stain remover, but it is a harsh chemical that requires special safety precautions. Wear long rubber gloves and protective eyewear, and observe the basic chemical safety rule of always adding the chemical water to and never adding water to the chemical.
Begin by filling a clean bucket with 2 cups of cold water and then carefully pouring in a quarter cup of acid, taking care to minimize splashes. Should any of the solution splash onto your skin, rinse it off quickly to prevent irritation. Next, slowly pour the solution over the rust stain and gently scrub the area with a stiff-bristle nylon brush. Wait a few minutes before washing off the solution with a garden hose. Major rust stains may require multiple treatments.
These cleaning techniques should keep your driveway looking great whatever comes its way.