Power Washing Pros · 715-446-4271 · powerwashingproswittenberg.com
The short version
Concrete is the one surface around a house that is meant to be pressure washed. A rotating surface cleaner covers the slab evenly, so there are no stripes or wand marks, and lifts the dirt, black film, tire marks and leaf stains that build up in the texture. Some stains — rust, deep oil, and the white salt of efflorescence — are in the concrete rather than on it and need their own treatment.
Signs it's time
- The driveway is two or three colors: grey in the sun, black along the shaded edge.
- Tire tracks where the cars park.
- Brown leaf shadows from last fall.
- A slick, dark film on the north side of a walk or on shaded steps.
- Stripes left behind from an earlier wash with a hand wand.
Why a surface cleaner, not a wand
Clean a driveway with a pressure washer wand alone and it comes out striped — every pass of the nozzle leaves a slightly cleaner line next to a slightly dirtier one. Up close it is hard to see; from the road it looks like a zebra.
A surface cleaner is a round housing with spinning nozzles underneath. It rides flat over the concrete, so every square foot gets the same treatment. The result is one even color from the garage to the street.
What comes out
The grey-black film of dirt and organic growth that builds up in the surface texture. Tire marks. Leaf tannin — the brown silhouettes left by wet leaves in the fall. Mud splash along the edges. The green and black slick on shaded walks, which is as much a slipping hazard as a looks problem.
What might not
Oil stains that have soaked in over years usually lighten but seldom vanish. Orange rust from well water, fertilizer or metal furniture is a chemical stain and needs a separate rust treatment. White powdery patches are usually efflorescence — salts coming up from inside the concrete — and pressure washing can actually make them come back.
Concrete also looks different from one pour to the next. A patched section, a newer apron or an old slab next to a new one will not match exactly, even when all of them are clean.
Sealing is a separate step
A clean driveway is the right time to seal concrete, if you want it sealed — sealer has to go on a clean, dry surface. It is a separate job from the cleaning. Ask about it on the call if it is something you are considering.
Wisconsin concrete takes a beating
Winter is hard on it: road salt tracked in on the cars, sand, freeze and thaw. A spring cleaning takes the salt residue and winter grime off before it has all summer to bake in, and makes it easy to spot any cracks and spalling that opened up over the winter.
What a wash will and won't do
Washing will
- Clean the slab to one even color, with no stripes
- Lift tire marks, leaf stains and ground-in dirt
- Take the slippery film off shaded walks and steps
Washing won't
- Fully remove old, soaked-in oil stains
- Remove rust stains — that is a separate treatment
- Fix cracks, spalling or an uneven pour