Methods
How do you safely remove moss and algae from a roof?
Safely removing roof moss and algae means a low-pressure treatment that kills the growth and lets it weather off, never a pressure washer. High pressure strips shingle granules and forces water under tiles. Shaded north-facing elevations and pavers usually need the same treatment.
The short version
Safely removing roof moss and algae means a low-pressure treatment that kills the growth and lets it weather off, never a pressure washer. High pressure strips shingle granules and forces water under tiles. Shaded north-facing elevations and pavers usually need the same treatment.
- Treatment kills the organism at the root so it doesn't return within weeks.
- Landscaping is pre-wetted and rinsed to protect plants.
- Pressure washing a roof commonly voids the manufacturer's warranty.
- Fixing the shade or drainage cause extends the result significantly.
Related questions
- How long does roof moss treatment last?
- Typically 18 months to three years depending on shade, tree cover and moisture retention.
- Is roof algae actually damaging?
- Yes — it holds moisture against the surface, which accelerates granule loss and can lift tiles over time.
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