How to get green film and algae off a wood deck before pressure washing
Stubborn green film, moss, and algae can cover decks and make them difficult to pressure wash without a pre-spray treatment. Moisture can also leave behind staining on older wood that needs low-risk fixes to look nicer.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Pre-treating the surface with a mixture of vinegar and Dawn dish soap and letting it sit for about 15 minutes before pressure washing.
- 2Scrubbing with dish soap and a brush
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
r/CleaningTips1 person · September 2026
“It has a green film everywhere with some moss or algae growing in spots. I'd like to make it easier to pressure wash - is there something good to pre-spray it with?”source ↗
letitgo99 · r/CleaningTips · 1 upvotes
r/HomeMaintenance1 person · September 2026
Where this came up
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