The short answer
Soft washing is the right choice for stucco. It uses low pressure and a cleaning solution to break down dirt, mildew and staining, then rinses gently. High-pressure washing can etch stucco, chip paint and force water behind the finish. Save high pressure for bare concrete and similar hard surfaces.
How soft washing works
Soft washing applies a cleaning solution at low pressure, close to what a garden hose puts out. The solution is given time to break down dirt, dust, mildew and staining, then it is rinsed away gently. The solution does the cleaning, not the force of the water.
How pressure washing works
Pressure washing uses a concentrated, high-pressure stream of water to blast dirt off a surface. On hard, durable surfaces like a concrete driveway, that works well, especially with a surface cleaner that spreads the pressure evenly.
What high pressure can do to stucco
- Etch or erode the stucco texture, leaving blotchy patches
- Chip or peel paint and elastomeric coatings
- Force water behind the stucco and around windows
- Widen small existing cracks
- Damage window seals, light fixtures and screens
Side-by-side comparison
| Soft washing | Pressure washing | |
|---|---|---|
| Pressure | Low | High |
| What cleans | The cleaning solution | Water force |
| Best for | Stucco, paint, siding, tile roofs | Bare concrete, pavers (carefully) |
| Risk to finish | Very low | Can etch, chip or force water in |
Questions to ask any cleaning company
- Do you soft wash stucco, or use a pressure washer on it?
- How do you protect plants and landscaping?
- What pressure do you use on pavers and decks?