Do you have those pesky black streaks on your roofs. It’s not mold. It’s probably not soot. It is a pervasive and prevalent algae known as Gloecapsa Magma. This algae grows a moisture-rich environment, usually supplied by the morning dew, the lack of direct sun, or shade. The first stains usually appear on the north-facing sides of a roof, which receives less light or areas with heavy tree coverage.
Like a cold, algae travels through the air, so if one neighbor receives a few algae spores, the whole neighborhood will soon be showcase the black streaks. Unfortunately, they love to feed on the calcium carbonate contained in most asphalt shingles. According to Tom Bollnow of the Asphalt Roofing Manufacturers Association (ARMA), “The algae is mostly an aesthetic nuisance, although with time, the moisture retained in the algae can prematurely age the shingles.”
So, how do you clean your roof? First of all, think SAFETY first. We recommend call a roof professional, like Rapid Roofers, especially if you have a steep roof. Secondly, the answer is “very carefully.” No pressure washing on your roof as this process will void your shingles warranty.
CLEANING YOUR ROOF
#1 – DO NOT USE CHLORINE BLEACH.
Bleach mixtures can injure sensitive plants. Because it is difficult to totally protect them from the mix, spray them down with clean water before applying any solutions for cleaning algae and immediately after, whether you cover them or not!
#2 – USE LOW PRESSURE APPLICATION.
Using a plastic pump-type garden sprayer, thoroughly soak the affected area with your choice of chemical. Allow it to sit for at least 5 minutes. Wash off all dirt and fungus residue. Again, we do not recommend pressure washing your roof!
#3 – WAIT FOR ROOF TO FULLY DRY.
Allow the roof to dry thoroughly. Inspect the roof for any remaining fungus… if it is slimy, or any sort of residue comes off on your hand,
repeat the above steps. You must let the roof dry before a second application of mix. A second application of cleaner will not have its full effect on a damp surface!
WHAT CLEANING PRODUCTS CAN I USE?
As a licensed and insured Atlanta Roofing Contractor, we, at Rapid Roofing, recommend the following products. Please, test a small portion of our roof to ensure the products fits your needs.
#1 – SPRAY IT & FORGET IT
Spray and Forget is a new product for cleaning algae that offers a long-term solution to fungus problems. It is sprayed on and allowed to dry without rinsing. Though it is slow-acting when compared to bleach solutions, it can prevent mildew growth for years! If you want to see quick results, you can do a one-shot bleach cleaning. Rinse thoroughly, allow to dry and then apply Spray and Forget according to the instructions.
#2 – OXYGEN BLEACH POWDERS
With a good oxygen bleach, you will great algae stains without exposing yourself and your family to toxic chemicals. Powdered oxygen bleach is made from natural soda ash or borax and hydrogen peroxide. Also, oxygen bleach works by releasing its oxygen once it is exposed to water. This leaves only borax or natural soda ash as the by products, both of which are non-toxic to humans, animals and plants making them ideal for the person trying to live an eco-friendly lifestyle.
#3 – MOSS OUT!
If you have moss as well, then here is a great product choice. Moss Out! comes in a number of formulations, one specifically for roofs and others designed to remove and/or inhibit moss and fungus growth on siding, masonry surfaces and even lawns. Their formula use tried and true zinc compounds that linger on surfaces to provide continuing protection from fungus regrowth.