The Simple Method
Step 1: Mix the Solution
Combine:
1 part bleach
3 parts water
(If using a commercial outdoor cleaner, follow the label instructions.)
Step 2: Apply Generously
Using a pump sprayer or hose-end sprayer, coat the affected siding from bottom to top. This prevents streaking.
Step 3: Let It Sit
Walk away for 10–15 minutes. The solution does the work for you, breaking down the algae at its roots.
Step 4: Rinse
Rinse thoroughly with a regular garden hose, spraying from top to bottom.
That’s it.
No scrubbing required.
Why This Works So Well
Bleach kills algae on contact and removes the green staining at the same time. Letting it sit allows the solution to penetrate and loosen buildup without mechanical scrubbing.
The rinse simply washes everything away.
It feels almost too easy.
Important Safety Tips
While this method is simple, keep these precautions in mind:
Protect plants by watering them before and after cleaning.
Wear gloves and eye protection.
Avoid mixing bleach with any other cleaners.
Never use this method on delicate wood without checking manufacturer guidelines.
How to Prevent Algae from Coming Back
After seeing how well this worked, I also picked up a few prevention tips:
Trim back overhanging branches.
Improve airflow around your home.
Install zinc or copper strips near the roofline (rainwater helps prevent growth).
Clean siding once a year before buildup gets heavy.
A Weekend Saved
What I expected to be an exhausting, scrub-heavy project turned into an easy afternoon task. Sometimes the best home maintenance tips don’t come from hardware stores—they come from neighbors who’ve already figured it out.
Now when I see that green film starting to appear, I don’t dread it.
I spray, wait, rinse—and enjoy a house that looks bright and fresh again, with almost zero effort.
