Soft wash basics for siding and roofs
Black streaks on a roof or mildew on stucco aren't pressure problems — they're chemistry problems.
What you'll learn
- Why high pressure blasts shingles and carves stucco — and what to use instead
- What sodium hypochlorite (SH) actually does to algae and mildew
- How to mix a safe homeowner-grade soft-wash ratio
- When to stop and call a pro (tile, slate, cedar shake, painted surfaces with chalking)
Step by step
- Wet down nearby plants with clean water. Cover anything sensitive.
- Pre-mix SH with water and a surfactant at a homeowner-safe ratio.
- Apply with a pump sprayer from bottom to top. Let it dwell 10–20 minutes.
- Rinse thoroughly with a garden hose, top to bottom.
- Re-water landscaping when done.
Safety note
Never soft wash in direct sun on a hot day — the SH dries before it works. Early morning or late afternoon.
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