Homeowners often use "pressure washing" as a catch-all term for any exterior cleaning, but there are actually two very different methods — and using the wrong one on the wrong surface can cause expensive, irreversible damage.
Understanding the difference between soft washing and pressure washing will help you make the right call for every surface on your property.
Pressure Washing: Raw Power for Hard Surfaces
Pressure washing uses high-pressure water — typically 1,500 to 4,000 PSI — to blast away dirt, grime, oil stains, and organic growth from hard, durable surfaces.
Best for:
- Concrete driveways and garage floors
- Sidewalks and walkways
- Brick and stone patios
- Pool decks
- Retaining walls (stone or concrete)
- Pavers
These surfaces are dense enough to handle the force without sustaining damage. Pressure washing removes embedded dirt, oil stains, tire marks, algae, and moss that no amount of scrubbing with a garden hose can touch.
Never pressure wash:
- Roofing shingles — strips granules, voids warranty
- Vinyl siding — drives water behind panels, cracks material
- Wood siding or cedar shakes — splinters and gouges the surface
- Stucco — blasts away the finish coat
- Painted surfaces — strips paint instantly
- Windows — can crack glass, destroy seals
Soft Washing: Chemical Cleaning for Delicate Surfaces
Soft washing uses low-pressure water (under 500 PSI) combined with specialized, biodegradable cleaning solutions. The chemicals — not the pressure — do the heavy lifting, breaking down and killing organic growth at the cellular level.
Best for:
- Roof shingles (asphalt, clay, metal)
- Vinyl, wood, and fiber cement siding
- Stucco and EIFS
- Painted surfaces
- Fences and decks
- Outdoor furniture
- Screen enclosures
Why soft washing results last longer
Here's what most people don't realize: pressure washing only removes surface-level growth. The roots of moss, algae, and mold remain embedded in the material, and they grow back within weeks.
Soft washing kills organisms at the root. The treatment continues working for days after application, and because the source is eliminated rather than just knocked off, results typically last 4-6x longer than pressure washing on the same surface.
Quick Reference: Which Method for Which Surface
| Surface | Method | Why |
|---|---|---|
| Concrete driveway | Pressure wash | Hard enough to withstand force; removes embedded stains |
| Asphalt roof | Soft wash | High pressure strips granules and voids warranty |
| Vinyl siding | Soft wash | High pressure drives water behind panels |
| Brick patio | Pressure wash | Dense material; removes deep-set grime |
| Wood fence | Soft wash | High pressure splinters and damages wood grain |
| Stucco walls | Soft wash | High pressure destroys the textured finish |
| Stone walkway | Pressure wash | Natural stone handles moderate pressure well |
The Alpine Approach: Right Method, Right Surface
At Alpine Roof and Gutter Cleaning, we never take a one-size-fits-all approach. When we assess your property, we identify every surface that needs cleaning and match it with the appropriate method:
- Your roof and siding get a thorough soft wash treatment
- Your driveway and walkways get professional-grade pressure washing
- Everything is protected — landscaping, fixtures, and delicate surfaces
The result is a comprehensive clean that's safe for every surface and delivers the longest-lasting results possible.
Not sure which method your home needs? Get a free estimate and we'll assess every surface and recommend the right approach.