Black and Green Discolouration on Your Exterior Paint
This year’s wet and mild winter has been a boon for early flowering bulbs, trees and scrubs. I’m sure this
year’s flower count will come out to be a record year. Spring flowers aren’t the only things thriving in
the mild wet weather. Mildew and algae is flourishing on our homes too.
Black or green discolouration shows up on our homes in sheltered areas. For example: soffits and
carport ceilings and especially on the north side walls. Mildew shows up as black spots or streaks and
algae green spots or streaks. Anywhere it’s moist and sheltered from the sun are prone to mildew and
The big problem with mildew and algae is that it’s ugly. Many people worry its permanent and they will
need to repaint to get rid of it. The good news is that if your paint is in good condition the mildew and
algae can be cleaned away. The recommended cleaning solution to remove mildew and algae is one part
household bleach, 3 parts water and laundry detergent or regular dish soap. Spray or wipe the solution
on the surface and let it sit for about twenty minutes. It’s important to make sure the cleaning solution
doesn’t dry out, so if it’s warm out you may have to add more solution to keep it wet.
After twenty minutes most surfaces just rinse off clean by spraying the area with a garden hose.
Stubborn areas may need a second application and/or scrubbing or gentle power washing. It may be
impossible to completely remove the staining from porous unpainted stucco, but painted stucco cleans
Make sure you’re protected if you’re going to do this task yourself. Wear eye goggles, rubber gloves and
clothes you don’t mind being bleached. You could always just call us at White Knight Painting, we will take care of it without any of the hassle.
Call us at 250-472-8465
e-mail us at: [email protected]
To find out how we can help you get rid of that pesky mildew and algae.