Home services guide
Soft washing vs pressure washing
They sound interchangeable, but using the wrong one can strip a roof or leave mold behind to grow right back. Here is the plain-English difference, and how to tell which your home actually needs.
Soft washing
Low pressure, about the force of a garden hose, paired with cleaning solutions that kill algae, mold, mildew, and lichen at the root. The solution does the work, not force.
Best for
Roofs, vinyl and painted siding, stucco, wood, screens, and any delicate surface where high pressure would cause damage.
Pressure washing
A high-pressure stream of water that mechanically blasts dirt and grime off hard, durable surfaces. Force does the work.
Best for
Concrete driveways and sidewalks, brick, pavers, and unpainted masonry that can take the force.
The one that matters: your roof and siding
The black streaks on a roof and the green film on siding are living organisms, not just dirt. Pressure washing can knock the surface layer off, but it does not kill what is rooted in, so it comes back. Worse, high pressure on a shingled roof strips the granules that protect it and can void the warranty. Soft washing kills the growth with the cleaning solution, so the surface stays clean far longer and the roof is never put under damaging force. Knowing which surface takes which method, and mixing the solution correctly, is the actual craft.
Why one company often does both
A crew equipped for soft washing almost always carries pressure-washing gear too, and picks the right method per surface. The overlap runs one way: a pressure-only operator may not be set up to safely soft wash a roof. When you hire, ask whether they soft wash roofs and siding, not just whether they pressure wash.
Common questions
What is the difference between soft washing and pressure washing?
Pressure washing uses a high-pressure stream of water to physically blast dirt and grime off hard, durable surfaces. Soft washing uses low pressure, about the force of a garden hose, combined with specialized cleaning solutions that kill algae, mold, mildew, and other organic growth at the root. Pressure washing relies on force; soft washing relies on the cleaning solution.
Can you pressure wash a roof?
No. High pressure strips the protective granules off asphalt shingles, can crack tile, and forces water under the roofing, and it often voids the manufacturer warranty. Roofs should be soft washed. The low-pressure solution kills the algae and moss without damaging the surface.
Which one lasts longer?
Soft washing typically lasts far longer on organic staining because it kills the organism rather than just rinsing the surface. Pressure washing alone removes what is visible, so algae and mold that were not killed tend to return sooner.
Do soft washing companies also pressure wash?
Usually yes. A company set up for soft washing almost always owns pressure-washing equipment too and chooses the right method for each surface. The reverse is not always true: a pressure-only operator may not be equipped or trained to safely soft wash a roof or delicate siding.
Find top-ranked soft washing companies near you