How often should you pressure wash a driveway?

Short answer

Pressure wash the driveway and walkways once a year. Spring is the time, after the winter's grit and before the sealer goes on if the driveway gets one. Unlike siding, concrete and asphalt can take real pressure, and the job goes fastest with a surface cleaner, the round attachment that spins a pair of jets under a hood. It takes 60 to 120 minutes and costs $0 to $100, the top end being a washer rental. A pro charges $100 to $300.

Why it matters

A driveway and the walks around a house take everything the weather and the cars drop: oil, tire rubber, leaf tannin, fertilizer, and in a shady spot, a slick green film of moss and algae. The film is the dangerous part. Wet algae on a walkway is as slippery as ice, and it grows exactly where people walk every day. A stain that sits for a year sets into the pores of the concrete and stops coming out.

Washing once a year lifts the film and the stains before they set, and it's the step that makes a driveway sealer work. Sealer over dirt peels. On asphalt, a wash also shows you the cracks that need filling before water gets into them and freezes.

When to do it more often

The index has no modifiers for this job, so the schedule stays yearly. The things that change it are the ones you can see:

A shaded walkway that's gone green and slippery, which is a hazard now, not at the next spring wash.
An oil leak from a car, which should be soaked up and cleaned while it's fresh.
A driveway that's about to be sealed, which needs a wash right before, whatever the date of the last one.

What you need

A pressure washer, with a surface cleaner attachment that leaves no stripes
Concrete degreaser, for oil and grease stains

Steps at a glance

Sweep the driveway and walks clear of leaves, gravel and loose debris.
Spray degreaser on oil stains and let it work for the time on the label.
Wet the whole surface, then apply detergent if the washer has a soap tip, working in sections.
Run the surface cleaner over the whole area in slow, overlapping passes, like mowing a lawn.
Switch to a fan tip for the edges, the joints and any stain the surface cleaner left behind.
Rinse everything toward the street or a drain, not toward the garage or the foundation.

You're done when the surface is one even color, no stripes show, and a wet patch dries the same shade as the rest.

Signs it's overdue

Oil stains, especially where cars park.
Moss or algae in shaded areas and along the edges.
A surface that's slippery when wet.
Dark discoloration that didn't used to be there.

DIY or pro

This is a moderate job, and the moderate part is the equipment. A washer with enough power for concrete is heavier and louder than the one for siding, and without a surface cleaner the fan tip leaves stripes that take a second pass to even out. The surface cleaner is the thing that turns a tedious afternoon into a steady hour, and it rents along with the washer.

A pro charges $100 to $300 and brings a washer with more power and a wider cleaner than most rentals, which matters on a long driveway. If the driveway is being sealed the same week, the sealing company will often wash it as part of the job.

Safety

Pressure: a concrete-strength washer puts out enough pressure to cut skin and etch a line into the driveway if the tip stops moving. Keep the wand moving, keep it pointed away from feet, wear closed shoes and safety glasses, and keep the spray off the siding and the car. Don't use a narrow tip on concrete unless you want it to show.

FAQ

What pressure do you need to clean a driveway?

More than siding needs. A washer rated for concrete, with a surface cleaner attachment, gives an even result. A low-powered electric washer will do a walkway but struggles on a whole driveway.

How do you remove oil stains from a driveway?

Soak up fresh oil with cat litter or sawdust, then apply a concrete degreaser, let it work, and pressure wash. Old stains may need a second round.

Can pressure washing damage concrete?

Yes, if the tip is too narrow or held still. It can etch lines and expose the aggregate. Keep the wand moving and use a wide tip or a surface cleaner.

Should you seal the driveway after pressure washing?

If the driveway gets sealed, washing first is the right order. Let it dry fully before the sealer goes on.