What the letter usually means
Most HOA letters about siding are about green algae or black mildew, usually on the shaded side of the house. Some also mention dirty driveways, walkways or fences. The letter usually gives you a deadline to clean it.
How it gets fixed
A soft wash removes algae and mildew from vinyl and fiber cement siding safely in one visit. If the letter mentions the driveway or walkways, those can be cleaned the same day with a surface cleaner.
Don't blast it yourself
It's tempting to rent a pressure washer, but high pressure on siding can crack it, strip paint, and push water behind the walls. It also leaves the roots of the growth behind, so the problem returns.
Keeping it from coming back
Washing once a year, keeping gutters clear so water doesn't spill down the siding, and trimming branches that shade the house all help.
Written by Marcus, owner of Southern Surface Solutions in Fuquay-Varina, NC.