If not the green discoloration may be mold.
Cleaning green algae off siding.
Borax can also be part of a permanent remedy for black mold treatment on vinyl siding or to clean mold from wood on your deck.
Create a mix of bleach and water 1 tsp.
Part 2 of 3.
To 1 quart and use it in the same power washer as step 1.
Fill a bucket with warm water and mix in the oxygen bleach powder according to the package directions.
Dip the scrub brush into the solution and test it to see if it is effective at removing the staining.
Mildew and algae on vinyl and wood use a solution made of oxygen bleach not chlorine bleach mixed with water.
Maintenance is the first step to preventing the build up of moss algae and mold.
Water stains remove with a mild detergent and water.
Borax solution for cleaning mold off vinyl siding another cleaning recipe that is highly effective at cleaning mold and mildew from vinyl siding is a borax solution applied with a soft brush.
To prevent streaking start at the bottom and work up towards the top.
Stains on wood cleanse with mild detergent mixed with water.
A good cleaner to try first is a mixture of 70 water and 30 white vinegar.
Step 2 dip a long handled soft bristled scrub brush into the cleaning solution.
According to the vinyl siding institute the best way is to use a soft cloth or an ordinary long handled soft bristle brush.
Mix your cleaning solution.
Spray the siding with water from the garden hose to remove loose dirt and debris.
You will need to use bleach to clean off micro organisms like algae and mildew.
Choose a cleaning solution that is appropriate for the type of growth you have on your siding.
Always test any type of cleaner on a small section of siding to be sure it doesn t stain streak or otherwise damage the siding.
Fill a bucket with a solution of 30 percent white vinegar and 70 percent warm water.
Test a small area.