How to Get Oil Stains and Mildew Off a Concrete Driveway

Concrete looks tough, but it's actually like a hard sponge. It soaks up oil, holds moisture, and gives mildew a place to grow. In DeSoto County, between the humidity, the shade trees, and red clay that washes onto everything, most driveways go from white to gray to black in just a few years.

Here's how to deal with the two most common problems: oil stains and mildew.

Fresh oil stains: act fast

If the spill is fresh, the goal is to soak up as much as you can before it sinks in.

• Cover the spot with cat litter, baking soda, or cornstarch
• Let it sit for several hours or overnight
• Sweep it up and repeat if it's still wet
• Scrub what's left with dish soap and a stiff brush, then rinse

This works well on new spills. It won't do much for a stain that's been sitting there for months.

Old oil stains: degreaser and patience

For older stains, you need a concrete degreaser from the hardware store. Apply it, let it sit for the time on the label, scrub hard with a stiff nylon brush, and rinse. Deep stains may take a few rounds.

Be realistic: oil that has soaked deep into the concrete may lighten a lot but never fully disappear. Hot water and the right degreaser give the best shot.

What about soda, oven cleaner, or brake cleaner?

You'll see a lot of home remedies online. Soda can lift a little surface oil but leaves a sticky residue. Oven cleaner and harsh solvents can work but are rough on your skin, your plants, and the concrete itself. We'd stick with a product made for concrete.

Mildew and black stains

The dark, blotchy look on most driveways and sidewalks isn't dirt. It's mildew and algae growing in the pores of the concrete, especially in shady spots and along the edges where grass keeps things damp.

Scrubbing with a brush and an outdoor cleaner can help on a small area, but on a full driveway it's a lot of work. Mildew also grows back fast if it's only knocked off the top instead of killed.

Pressure washing the right way

A pressure washer is the right tool for concrete, but how you use it matters. A single wand held close to the surface leaves zebra stripes and can etch the concrete, roughing up the top layer so it stains even faster next time.

Pros use a surface cleaner: a round attachment with spinning nozzles that keeps the pressure even and the distance consistent. Then the concrete is treated to kill mildew so it stays clean longer. That's the difference between a driveway that looks better and one that looks new. If you're curious why we treat siding differently, see soft washing vs pressure washing.

Don't forget the red clay

Orange red stains from our clay soil are their own problem. They often need a specific rust and clay remover rather than more pressure. If you have a lot of runoff onto the driveway, fixing the drainage or edging helps keep it from coming back.

Keeping it clean

• Put a drip pan or mat under cars that leak
• Clean up spills the same day
• Trim back plants that shade the concrete
• Make sure gutters and downspouts drain away from the driveway
• Plan on a professional cleaning every year or two

When to call a pro

If the whole driveway has turned gray or black, or you have patios, sidewalks, and a pool deck to do too, a professional cleaning is usually faster and safer for the concrete. Our driveway and patio cleaning takes off oil, mildew, and years of grime. We're in Horn Lake and Olive Branch every week, and a quote by text is free.