Why high pressure causes problems
Vinyl siding overlaps like shingles to shed rain. A strong spray aimed upward drives water behind the panels, where it can soak sheathing and insulation. Close-range high pressure can also crack or dent panels.
How soft washing works
Soft washing applies a cleaning solution at low pressure, lets it work on mildew and algae, then rinses gently. It cleans the growth instead of just blasting the surface.
If you do it yourself
- Use a wide tip and the lowest effective pressure.
- Keep the nozzle a few feet away and spray downward.
- Close windows and cover outdoor outlets and fixtures.
- Protect plants by wetting them before and after.
- Stay off ladders with a pressure washer; use an extension wand.