Power Washing Pros · 715-446-4271 · powerwashingproswittenberg.com
The short version
Pressure washing cleans with force: a narrow, high-pressure stream that scours dirt off hard surfaces like concrete. Soft washing cleans with a cleaning solution: it is applied at low pressure, left to work, and rinsed off. Siding, soffits, fences and most wood get soft washed. Driveways, sidewalks and other hard flatwork get pressure washed.
Which method for which surface
- Siding, soffits, trim and gutters — soft wash.
- Painted surfaces and old aluminum siding — soft wash, gently.
- Wood decks, docks and fences — low pressure, with the grain.
- Concrete driveways, sidewalks, garage floors and steps — pressure wash.
- Pavers and stamped concrete — pressure, used with care for the joint sand and the finish.
Pressure washing: force does the work
A pressure washer pushes water through a small nozzle at high pressure. On a hard, dense surface — a concrete driveway, a sidewalk, a garage floor — that force is exactly what you want. It gets into the texture of the concrete and lifts the ground-in dirt, tire marks and black film that a hose never would.
The same force is the problem everywhere else. It can drive water up behind siding panels, strip paint, gouge and fur up wood, blow out window seals and etch soft stone. A pressure washer is a tool for flatwork, not for the house.
Soft washing: the cleaner does the work
Soft washing flips it around. Instead of relying on force, a cleaning solution is put on at low pressure — closer to a garden hose than to a pressure washer — and given time to dwell. It breaks down the dirt and kills the algae, mildew and mold growing on the surface. Then it is rinsed off.
Because it kills the growth instead of just knocking the top layer off, a soft-washed house stays clean longer. And because nothing is being forced at the surface, nothing gets damaged in the process. It is the method vinyl siding manufacturers ask for.
Most properties need both
A typical job is not one or the other. The house gets soft washed. The driveway and walks get pressure washed. The deck gets something in between — low pressure, with the grain. Picking the method surface by surface is most of what separates a good wash from a damaging one.
Why a rental pressure washer goes wrong on siding
The most common damage on a house comes from pressure washing it with a machine and a narrow tip meant for concrete. Water gets forced behind the laps of the siding and into the wall. Paint and the chalky surface of old aluminum siding come off in stripes. Soffit vents and window screens get blown out.
Even when nothing is visibly damaged, the result often doesn't last: the growth is knocked back but not killed, so it returns within a season.
Is the cleaning solution safe for plants?
Plants and beds along the house are wetted down before any cleaning solution goes on, and rinsed again afterward. A plant that is already wet doesn't take up what lands on it the way a dry one does, and the rinse washes off anything that did.
If something along the walls is especially delicate or valuable, mention it on the call.
What a wash will and won't do
Washing will
- Clean siding, soffits and trim at low pressure, without forcing water into the wall
- Kill algae and mildew rather than just knocking them back, so it stays clean longer
- Use real pressure on concrete, where it belongs, to lift ground-in dirt
Washing won't
- Put high pressure on siding, painted surfaces or old aluminum siding
- Reverse sun-faded or chalky siding, whichever method is used — see the oxidation guide
- Remove rust stains, which need a separate treatment