The short answer
Pressure washing uses high-pressure water to blast dirt, oil and grime off hard surfaces like concrete, pavers and brick. Soft washing uses low pressure, about like a garden hose, with a cleaning solution that kills mold, mildew and algae. Use pressure for driveways and sidewalks; use soft washing for roofs, siding, stucco and screens, which high pressure can damage.
What is pressure washing?
Pressure washing sprays water at high pressure to physically knock dirt, mildew, oil and grime off a surface. It's fast and effective on hard, durable surfaces that can take the force: concrete driveways, sidewalks, pavers, brick and some patios.
The same force that makes it effective on concrete is what makes it risky elsewhere. Aimed at the wrong surface, high pressure can etch stucco, strip paint, force water behind siding, tear screens and knock the protective granules off roof shingles.
What is soft washing?
Soft washing relies on chemistry instead of force. A cleaning solution is applied at low pressure, left long enough to kill the mold, mildew and algae, and then rinsed off gently. Because it kills the growth rather than just blasting off the surface layer, results usually last longer, too.
Soft washing is the standard method for roofs, siding, stucco, painted surfaces, screen enclosures and anything else that's easy to damage.
Which surfaces need which method?
| Surface | Method | Why |
|---|---|---|
| Asphalt shingle roof | Soft wash | High pressure can strip the granules that protect shingles. |
| Vinyl siding | Soft wash | Pressure can force water behind the panels. |
| Stucco and painted block | Soft wash | Pressure can etch the surface and lift paint. |
| Pool cages and screens | Soft wash | Screens tear and pop out of their channels under pressure. |
| Concrete driveways and sidewalks | Pressure wash | Durable, and dirt sits deep in the pores. |
| Pavers | Pressure wash (with care) | Clean without blowing out the joint sand; seal afterwards. |
| Wood decks and fences | Low pressure | Wood fibers raise and splinter under high pressure. |
Why you shouldn't pressure wash a roof
The black streaks on Florida roofs are algae, mostly a species called Gloeocapsa magma. The Asphalt Roofing Manufacturers Association recommends against using high-pressure washing to remove it, because the force can loosen the granules that shield shingles from the sun. A soft wash kills the algae with a cleaning solution and a gentle rinse instead.
Rule of thumb: if a surface is soft, painted, coated or delicate, it should be soft washed. If it's bare concrete or masonry, pressure is usually fine.
Is DIY pressure washing worth it?
For a small patch of concrete, maybe. But rented pressure washers make it easy to leave stripes and wand marks in concrete, etch surfaces or damage siding and screens, and they can't safely soft wash a roof. Ladder work on a two-story house or a roof is also where most DIY injuries happen. A professional crew brings the right equipment and cleaning solutions for each surface and protects your landscaping while they work.
How Costa's handles it
We use whichever method is right for each surface: soft washing for roofs, soft washing for siding and stucco, gentle cleaning for screen enclosures and pressure washing for driveways and concrete. If you're not sure what your home needs, call (386) 679-6569 or send us photos for a free estimate.
Common questions
Is soft washing as effective as pressure washing?
On roofs, siding and screens, it's more effective, because the cleaning solution kills mold, mildew and algae at the root instead of just knocking off the surface layer.
Can soft washing hurt my plants?
A careful crew protects plants before cleaning and rinses them afterwards. We protect your landscaping and clean up the work area when we're done.