Homeowners often use "power washing" to mean any exterior cleaning, but there are two different methods and they aren't interchangeable. Pressure washing uses high-pressure water to blast dirt off hard surfaces. Soft washing uses low pressure and a cleaning solution to kill and rinse away algae, mildew, and grime on surfaces that high pressure would damage. Picking the right one is the difference between a clean house and a repair bill. Here's how to tell which your home needs.
The Short Answer
Soft wash your siding and roof; pressure wash your concrete and other hard, durable surfaces.
Most Fox Valley homes need both. The siding and roof get soft washed because they're delicate and the problem is usually organic growth. The driveway, sidewalks, and patio get pressure washed because they're tough and the problem is ground-in dirt, stains, and residue.
A good exterior cleaning company will match the method to each surface on the same visit rather than running one machine over everything.
What Pressure Washing Is
Pressure washing uses a concentrated, high-pressure stream of water to physically strip dirt and stains off a surface.
It works best on hard, non-porous or very durable materials: poured concrete driveways, sidewalks, garage floors, brick pavers, stone patios, and some fencing. Professionals often use a surface cleaner, a spinning attachment that cleans flat concrete evenly without leaving stripes.
On concrete, pressure washing removes tire marks, mildew, ground-in dirt, and the white residue left behind by winter road salt. It's the right tool when the stain is sitting on top of a surface that can take the force.
Pro Tip: If your driveway looks striped or blotchy after someone else pressure washed it, that's usually wand marks from cleaning flat concrete without a surface cleaner. A professional surface cleaner gives an even finish.
What Soft Washing Is
Soft washing applies a diluted cleaning solution at low pressure, lets it work, and then rinses it off gently.
The solution does the cleaning instead of the water pressure. It kills the algae, mildew, and mold that cause green and black streaks, so the growth is removed at the root rather than just blasted off the surface. Because the organisms are killed, the surface usually stays clean longer than it would after a pressure rinse alone.
Soft washing is the right method for vinyl siding, painted wood, fiber cement, stucco, EIFS, asphalt shingle roofs, and anything with seams, laps, or coatings that high pressure could force water behind or strip away.
Which Surfaces Get Which Method
Soft wash: vinyl and aluminum siding, painted wood and fiber cement siding, stucco and EIFS, asphalt shingle roofs, soffits and fascia, gutter exteriors, and painted or vinyl fences.
Pressure wash: concrete driveways, sidewalks, front stoops, garage aprons, brick and stone pavers, and unpainted concrete walls.
Either, depending on condition: brick walls and wood decks. Brick and wood can handle moderate pressure, but older mortar and soft wood fibers are easy to damage, so a lower-pressure approach is often the safer choice.
Pro Tip: When in doubt, ask whether the surface has seams, paint, or granules. If it does, it should be soft washed.
Why the Wrong Method Causes Damage
High pressure on the wrong surface causes damage that is often expensive and sometimes hidden.
On vinyl siding, a pressure wand can drive water up behind the laps and into the wall, where it can lead to moisture problems you won't see right away. It can also crack brittle older panels. On painted wood, it strips paint and raises the grain. On asphalt shingles, it knocks off the protective granules, which shortens the life of the roof.
Going the other way is mostly a matter of results. Soft washing a concrete driveway won't lift tire marks or ground-in dirt the way pressure will.
What Fox Valley Homes Usually Need
Most homes in Geneva, St. Charles, Batavia, and the surrounding towns need a soft wash on the siding and a pressure wash on the concrete.
Our humid summers are hard on siding. The north-facing side of a house gets the least sun and stays damp the longest, so that's where green algae shows up first. Homes under mature trees along the Fox River see it sooner. Black streaks on roofs are also common here and are usually algae, not dirt.
Concrete takes a different beating. Winter road salt tracked onto driveways and walks leaves residue, and freeze-thaw cycles open up the surface so dirt settles in deeper. A spring pressure wash after salt season clears that out. Late spring also brings cottonwood fluff, which sticks to damp siding and screens and is easiest to rinse off once it's done falling.
Is Soft Washing Safe for Plants, Pets, and Windows?
Yes, when it's done carefully: a professional crew protects plants and rinses thoroughly.
Before applying solution, we wet down landscaping so plants don't absorb it, and we rinse beds and lawn edges again afterward. Pets and kids should stay inside until the surfaces have been rinsed. Windows on the area being washed are rinsed as part of the job, and many homeowners pair a soft wash with exterior window cleaning so the glass matches the clean siding.
Getting the Right Service
Ask for a quote that lists each surface and the method being used on it.
Foxy's offers pressure washing for driveways, walks, and patios, soft washing for siding, and roof cleaning for streaked shingle roofs. We assess each surface on-site and put the method for each one in writing before we start.
Foxy's Window Cleaning · Geneva, IL
Not sure which method your home needs? Request a free estimate and we'll walk the exterior and recommend soft washing, pressure washing, or both, surface by surface.