Many homeowners have had their roof fall victim to unsightly algae and moss . This is a common occurrence in areas that experience high levels of humidity. Aside from high humidity, algae can also be carried to your roof through airborne spores. Seattle is located in the national danger zone for roof moss and lichen. Fortunately, today’s homeowner has the option to choose algae resistant shingles, also known as AR shingles, to avoid this problem.
The History of Algae Resistant Shingles
Algae resistant shingles date back to the 1980’s when roofing materials were produced that contained alternative kinds of mineral granules, such as:
- Galvanized Metal Powder
When AR shingles were first produced in the 1980’s, they were considered to be a premium option in roofing materials. By the 1990’s, algae resistance became a standard option and was available in most brands of shingles.
How Do Algae Resistant Shingles Work?
AR shingles work by using copper that is included in the roofing granules that make up the shingles. The copper is not noticeable to the eye; however, it will keep algae from being able to survive on the surface of your roof. The copper or zinc materials found in AR roofing materials also respond to rain which activate the algae fighting action. Moisture generally works to help promote the growth of algae, but with these special shingles, it helps to further protect the roof.
AR shingles tend to be more expensive initially, but when considering the cost of having to have the algae removed from your roof on a yearly basis, they are well worth the initial investment and will help to protect your roof for many years to come.
How Effective Are Algae Resistant Shingles?
Some brands of algae resistant shingles can help keep your roof free from unwanted moss and algae for up to 20 years. Products containing copper have been reported to be ten times more effective than zinc at keeping algae at bay. The copper is generally time released and will work to resist algae and moss build-up over a long period of time.
It is also important to note that adding some type of copper ridge or hip shingle containing copper will not work on an existing roof system that already has live algae or moss present. It will not kill the algae, but rather works to provide resistance to it before it starts.
No one wants to think of fungus taking over their roof, causing damage as well as ugly staining. In choosing algae resistant products when replacing a roof, you may be spending more money upfront, but for the protection and peace of mind that comes with it, it’s worth it.