4. Exact Ratios to Keep Your Siding Safe
Sticking to the right proportions is important. Too much vinegar could potentially dull delicate paint finishes.
The safe formula is:
1 cup vinegar per 1 gallon of water
If you’re unsure about your siding, test a small hidden area first. But in most cases, this ratio is both safe and highly effective.
5. How to Apply It — No Ladders, No Scrubbing
Pour the mixture into a garden sprayer and spray the affected areas.
Start at the bottom and work your way upward to ensure even coverage and avoid streaking. The sprayer allows you to reach higher areas safely from the ground.
Be generous when applying — the surface should be thoroughly saturated so the solution can penetrate the algae properly.
And then… you wait.
6. The “Let It Sit” Step That Does All the Hard Work
This is the most important part.
Let the solution sit for 20 to 30 minutes. For heavy buildup, you can leave it for up to an hour.
During this time:
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The vinegar breaks down the algae
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The soap loosens its hold on the siding
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The growth begins to detach naturally
Resist the urge to scrub. Patience is what makes this method so effective.
7. Rinse — and Watch the Algae Slide Off
After the waiting period, grab your garden hose with a spray nozzle and rinse from top to bottom.
You’ll notice something satisfying:
The algae comes off with minimal effort — often without any scrubbing at all.
The gentle water pressure is enough because the solution already did the heavy lifting.