Yes, in most cases, with care
Hairline and settlement cracks are normal in LA concrete. Washing over them with a rotary surface cleaner at moderate pressure will not make them grow. The spray stays parallel to the surface and keeps moving, so it cleans the slab without digging into openings.
The risk comes from pointing a narrow tip straight into a crack or joint. A concentrated stream can blow out loose concrete at the edges, flush out sand or soil underneath, and strip caulk or foam backer rod from expansion joints. That makes a cosmetic crack look worse and lets more water get under the slab.
What actually happens inside a crack
A crack collects soil, leaves and seeds, and weeds take root there. When you clean, you want the dirt on top removed and the crack rinsed, not excavated. Fill material is another story. Old caulk in control joints is often brittle, and a hard stream will peel it out in strips. Sometimes that is fine because it needed replacing anyway, but it is better to decide that before you start rather than discover it mid-wash.
Water itself is not the enemy. Southern California rainy season soaks driveways every winter. The concern is high-velocity water forced into a void, which can wash away base material and leave a hollow under the edge.
Repair first, or clean first?
For most crack repairs, clean first. Caulk and crack fillers bond poorly to dirt, oil and organic growth. A thorough clean, followed by a full day or two of dry weather, gives the filler a sound surface to grip. Many people schedule cleaning a few days before a sealing or crack repair project for exactly that reason.
Repair comes first when pieces are loose. If a corner rocks when you step on it, a chunk is spalling away, or one slab edge has lifted into a trip hazard, pressure washing will not help and may break off more material. Have that section assessed. Our guide on pressure washing versus replacing concrete covers how to tell cosmetic wear from structural problems.
How to wash a cracked driveway the right way
Sweep or blow off loose debris. Pull weeds out of cracks by hand instead of blasting them. Pre-treat oil spots and organic staining so the cleaning solution does the heavy work. Then run a surface cleaner in even, overlapping passes, crossing cracks rather than following them lengthwise.
Rinse with a wide fan tip held at a distance, angled across the crack rather than into it. Work from the top of a sloped driveway downward, so dirty water flows away from the area you just cleaned. Afterward, look over the joints. If filler came loose, note it for repair once the concrete is dry.
What to expect afterward
Cleaning often makes cracks more visible at first. Dirt that blended them into a uniformly gray slab is gone, so the lines show up sharper. Some homeowners are surprised by this. It is not new damage, just a clearer view of what was already there, and it is useful information if you are planning repairs.
Rust, root heave and settlement cannot be washed away. A clean surface will look much better overall, but a crack is a crack until it is filled or the section is replaced.
Give the slab time to dry before you judge it. Wet concrete looks darker and more uniform. Once dry, cracks that held water may stay dark for a while longer than the rest of the surface, because the water drains out of them slowly. That evens out within a day or so of dry weather.
Pricing and next steps
If you are about to repair cracks, clean the whole driveway rather than just the cracked areas. Filler on a freshly cleaned joint next to dirty concrete stands out, and an evenly clean surface makes the repair blend in better. It also gives you an honest look at how many cracks there really are before you buy materials or hire someone.
As of October 2026, driveway cleaning on our calculator is $0.50 per square foot, with a $195 minimum per visit. A 600 square foot driveway works out to $300 before any bundle discount. Say Wash It walks the driveway with you at the end, which is a good time to point out any joints or cracks you want to address next.
Key points
Yes, in most cases, with care
Hairline and settlement cracks are normal in LA concrete. Washing over them with a rotary surface cleaner at moderate pressure will not make them grow. The spray stays parallel to the surface and keeps moving, so it cleans the slab without digging into openings.
Repair first, or clean first?
For most crack repairs, clean first. Caulk and crack fillers bond poorly to dirt, oil and organic growth. A thorough clean, followed by a full day or two of dry weather, gives the filler a sound surface to grip. Many people schedule cleaning a few days before a sealing or crack repair project for exactly that reason.