Why Homes Turn Green North Georgia
If you live in North Georgia, you’ve probably noticed houses turning green on the shaded sides. This is not dirt and it is not mold inside your siding. It is airborne algae that thrives in humid climates and attaches to exterior surfaces over time. The problem is extremely common in Barrow, Gwinnett, Jackson and Hall County because of tree cover, pollen and moisture retention.
Homes in Winder, Braselton, Hoschton, Statham and Auburn develop this discoloration faster because neighborhoods in this part of Northeast Georgia are heavily shaded and built on moisture retaining clay soil. These conditions allow algae to stay damp for longer periods compared to open or dry regions.
It is not dirt, it is living algae
The discoloration is caused by a bacteria called gloeocapsa magma. It travels through the air and feeds on limestone filler found in siding, paint and roofing materials. Once attached, rainwater alone cannot remove it because it roots into microscopic pores of the surface.
Why homes here develop it faster
- dense tree shade
- humid summers
- heavy spring pollen
- north facing siding stays damp
- morning dew retention
Where it usually starts
- north side of house
- under gutter lines
- behind downspouts
- vinyl siding seams
- roof shingles
Why blasting it with pressure does not work
High pressure only removes the surface color. The organism remains embedded and returns quickly. This is why many homeowners see the green come back within months after using a pressure washer.
How it is actually removed
The algae must be treated, not blasted. A softwashing solution neutralizes the organism at the root so it cannot regrow rapidly. The surface is then rinsed at low pressure to protect siding and roofing materials.
Safe removal for homes in North Georgia
Is green siding mold?
No. It is airborne algae. Mold grows from inside organic material while this growth feeds on minerals in siding and roofing surfaces.
Will rain wash it away?
No. Rain actually helps it spread because moisture activates the organism.
How fast does it return after pressure washing?
Usually within months because pressure removes the color but not the root structure.
Is it damaging the house?
Over time it breaks down protective coatings and shortens the life of paint and roofing materials.