Begin by spraying a 5 foot wide section of the siding from the ground to the top.
Black stains on vinyl siding.
Before attempting to remove stains it is best to clean the area with a general cleaner.
Never use chlorine bleach to remove insect stains as it will seep into the ground and kill the roots of any vegetation in the area.
By the growth pattern we think this is almost certainly a dark colored algae.
But testing is probably not justified.
Thankfully regular maintenance of your vinyl siding is fairly straightforward and simple.
Bleach works but if the house is in a generally damp area and the siding is facing north the mold fungus will just come back.
For tough spots like paint drips tar and pencil and pen marks use a nonabrasive bathtub cleaner or nylon scrub pad.
You basically have to stay on top of it remove any tree branches that are up against it make sure your waterspouts or gutters aren t keeping it wet a lot and ask at the hardware if there is anything you can apply to slow down growth.
Scrub the area with a scrub brush and the solution.
The black stains on the vinyl siding shown at left may be a fungus or a black agae.
Over time and through repeated changes in weather vinyl siding will attract and develop mold or.
Protect yourself with rubber gloves and goggles.
Pour the cleaning solution into a power washer.
A microscopy lab examination of a sample from this surface would be needed to know for sure.
Remember not to angle the sprayer upward to keep the solution from seeping under the siding layers.
Although it s most often found on the east coast it can grow anywhere and especially thrives in areas that have cool damp springs or rainy fall weather conditions.
Mix a strong solution of siding cleaner or other strong detergent and hot water.
If you are worried about damaging the vinyl you may use a lower pressure pump sprayer.
How to clean spots on vinyl siding general cleaning tips.
The black tar like spots that are all over your vinyl siding are more than likely a fungus called sphaerobolus stellatus better known as artillery or shotgun fungus.