Avoid wire brushes or very abrasive pads, which can scratch or damage siding.
Step 6: Rinse Thoroughly
Rinse the wall thoroughly with clean water from top to bottom.
Continue rinsing until no cleaner or loosened algae remains.
Once the siding dries, the difference is usually dramatic.
Why I Wouldn’t Start With a Pressure Washer
A pressure washer can clean siding quickly, but more pressure is not always better.
Used incorrectly, high-pressure water can:
force moisture behind siding
damage paint
mark softer materials
loosen panels
damage caulking around windows and doors
For ordinary algae, allowing an appropriate cleaner to do most of the work is often safer than trying to blast the stain away.
If you do use a pressure washer, follow the siding manufacturer’s recommendations and use the lowest effective pressure.
Siding
What About Household Bleach?
Diluted chlorine bleach is sometimes used for exterior algae and mildew, but it requires extra caution.
