I live north of the equator in a humid climate. The 2 north-facing windows pictured below only get direct light (lots of it) in the evening. We get a lot of rain. There is green mold growing from the windows for some reason.
I want to
- determine why I'm getting this mold
- clean off / get rid of the mold
- prevent it from coming back without having to replace the windows.
The white on the stucco between the lip of the window and the stucco is unpainted white caulk that has been there for 2 years, and that I should have painted, and will once I clean off the mold.
Click for full size image
Best Answer
Mold and/or mildew (yours looks like mildew, but no big difference in regards to abatement) are both fungi and will grow where dark and damp conditions exist.
1) The cause is moisture.
2) You can clean if off easily with a scrub brush and soap, but to help prevent regrowth you should chemically kill it. A 1/4 cup bleach/1 gal. water solution will work or there are numerous consumer cleaners with bleach that will do it.
3) Take steps to keep the area dry, like rain gutters, an awning over the window, etc. Thoroughly clean, caulk and paint the stucco with a good quality exterior paint (most have mildew growth inhibitors). Chemically killing it will help prevent regrowth but be prepared to repeat if moisture cannot be controlled.