Oil from an old or leaking car can leave big nasty stains on your concrete driveway that are an eyesore and a slipping hazard. You should take care of these dirty spots right away before they set in on your concrete. Fortunately, the task isn’t too difficult. With the right materials and tools, you can clean this mess up in no time.
A quick and easy way to clean oil stains from a concrete driveway is to use a pressure washer. After absorbing the excess oil up from visible oil puddles, use a hot water pressure washer to clean out any residual oil that has stained or penetrated the concrete surface. The force from a medium-duty pressure washer with a PSI rating between 2000 and 3000 PSI will make quick work of the cleaning job.
Cleaning up an oil stain on a concrete surface is pretty straightforward. Let me go more into detail about what you’ll need to start and what steps you’ll take to have your driveway looking clean and new again.
Steps For Pressure Washing A Concrete Driveway
Clear your driveway of any obstructions. This might include any cars, recreational vehicles, storage items, and even your kid’s toys. Then do a quick sweep of your driveway using a large push/utility broom, removing any debris such as small stones, twigs, leaves and dirt.
Soak up fresh oil stains with an ample amount of baking soda, corn starch or kitty litter. These are all common and inexpensive items that can be found around the house or in your local market and hardware store. Start by pouring and spreading an even amount on top of the excess oil. Give it about 20-30 minutes for the stains to be absorbed. For bigger oil puddles let the absorbent material sit overnight.
Use a push broom to sweep into a dustpan for disposal. Follow that with a scrubbing of the remaining surface stain. As hard as concrete might appear to be, it is still porous. That means it’s still possible for oil to seep into some of its small holes. This will definitely show when oil stains are given time to dry and set. So you should definitely try to clean any oil spills when you first spot them.
For stains that have dried somewhat into the concrete a deeper cleaning is required. Apply a generous dose of degreaser solution onto the affected area. Give the solution about 5-10 minutes to loosen up the stains. Then, using a circular motion, scrub the stain with a stiff nylon bristle brush.
Sweep up the remaining oil clusters and then rinse off with water. You can also hose off the entire driveway at this time to wet it in preparation for detergent application.
Set up your pressure washer. A hot water pressure washer will work better in this situation, simply because hot water has a way of breaking down oil and grease on a molecular level. Think about how much easier it is to wash oily and dirty dishes with hot water than with cold. A regular cold water pressure washer will also work.
Make all the connections, which will involve attaching a garden hose to the washer, a pressure washer wand to the pressure hose, and a pressure washer nozzle to the wand.
Select the black colored pressure washer nozzle. Pressure washer nozzles are universally color coded. The black one is used for dispensing detergent because it has a low pressure spray and it also has the widest spray angle at 65 degrees.
Prepare a concrete cleaning detergent. There are ones that are specifically used in pressure washers. Some pressure washers have a detergent tank that you can pour the detergent into. Others will require a siphon hose to carry the detergent from an external source into the washer unit.
Spray down the driveway using sweeping strokes. Hold the wand about 12 inches away from the concrete. Make sure to cover all the surfaces with a layer of detergent. For easier execution, work in small sections going back and forth and overlapping each stroke by a couple of inches.
Allow the detergent to soak into the concrete for a couple minutes so that it can do its job of loosening up the oil, dirt and grime that has gotten into the surface pores. Be sure not to let the detergent dry out.
Switch to a medium pressure washer nozzle to rinse the driveway with. This will be the nozzle with a yellow colored tip. The yellow nozzle has a more narrow opening than the black one, and the effect of this is a more forceful and focused 15 degree spray. Most websites recommend the yellow nozzle for concrete surfaces.
Be careful about selecting other colored nozzles, such as those with a red or blue color tip. These two nozzles exert the most force and the water pressure may chip or severely damage the concrete surface if you’re not careful.
Red nozzles have zero degree spray angles and pretty much spray a direct line of water at aimed target. Blue nozzles also have zero degree spray angles but have an added rotary turbo spray function. They nozzles spin very fast while dispensing a zero degree spray. If you do decide to use either of these nozzles for extremely stubborn and difficult oil stains, first test out the spray on an inconspicuous area before proceeding with your cleaning.
After the nozzle switch has been made, rinse out the detergent from the driveway with the same pattern you used when you first sprayed detergent on. When you get to the oil spots, spend a little bit more time sweeping the area so that the pressure can lift and wash away the detergent filled oil from the concrete surface pores. You could also bring the wand closer to the surface for the same effect.
Wait until the concrete driveway has completely dried. Then apply a concrete sealant to protect against future stains and harsh weather elements. Do this by using a paint roller.
I recommend attaching an extension pole to the paint roller. Pour the sealer into a paint can for easy access. You can apply the sealer onto the concrete driveway like you would if you were painting a wall of a house. The extension pole will be a lifesaver, helping you avoid crouching on your knees while applying the sealant.
Wait for the sealant to dry. This might take a couple of hours. Then apply a second coat of sealant. The second coat should be applied in the opposite direction or at right angles to the first coat.
Give the second coat of sealant 24 hours before you use or park on the driveway again.
Attachments That Make The Job Easier
A push broom, or what some call a utility broom, is basically a broom with a wide brush attachment. I’m sure you’ve seen these around. A lot of construction workers use push brooms to sweep because it covers much more area with its wide brush. It’s also very durable. The brush is usually made out of stiff bristles. You work a push broom primarily by pushing the debris into a pile to be discarded.
A water broom attachment looks like a push broom except it has multiple nozzles lined up horizontally at the end. This will allow you to cover a wider area with fewer passes. You would connect it to your pressure hose instead of the wand and use it to rinse out the detergent.
A pressure washer surface cleaner attachment looks similar to a water broom except it has a spinning arm at the end that has multiple nozzles fixed on it. The spinning action provides for an even distribution of the spray and is helpful when working large surface areas, such as on a driveway.
Oil stains on a concrete driveway are commonplace occurrences. Whether they be actually on your driveway or inside your garage, they are a nuisance. Make sure you quickly clean up any oil spills that you have or else they’ll set in and you’ll need to spend more time cleaning the mess up. You can use a pressure washer to clean the oil stains out fairly easily. It’s fast and inexpensive to do. You might even find it fun blasting away grease, oil, dirt and grime.