Have you noticed dark streaks forming across your roof? If so, this is most likely caused by algae. It's a problem that makes a roof very unattractive but can also cause deterioration to the shingles underneath. Here is what you need to know about those dark roof streaks.
What Is Algae?
Algae is essentially a fungus that grows on a roof. It can easily appear in areas that are shaded due to other parts of the home or overhanging trees that cast shade. That is because algae love humidity and shade, and the right conditions can cause it to grow quite easily. Algae has a problem survivor if it touches copper or zinc. This is why algae won't grow in parts of the roof located underneath galvanized steel or flashing that has a coat of zinc on it.
How Is Algae Removed?
Removing algae can be a DIY project, or it can be done by a professional roofer. You'll need to make a cleaning solution by combining water (4 parts), chlorine bleach (1 part), and trisodium phosphate (1 part). You can also buy a commercial cleaning solution at your local home improvement store.
Spray the solution onto the algae and let it soak in for about half an hour, then rinse off the algae with your garden hose. Avoid using a pressure washer, since the equipment can easily damage shingles. If you can't get rid of those dark streaks, try using a soft scrub brush on the shingles. You can use an extendable pole to scrub, so you don't actually walk on your roof.
If you have plants that surround your home, cover them with plastic so that cleaning solution does not harm them when it falls off the roof.
How Is Algae Growth Prevented?
The best way to stop algae growth is to install a metal roof cap. It is placed at the peak of your roof and causes small pieces of zinc to flow down the roof each time it rains. Since algae need moisture to grow, you'll be coating the roof with that protective material by having the roof cap installed.
How Is Algae Damage Corrected?
You can always replace individual shingles that have been damaged by algae. This will ensure that the roof deck beneath it has protection from the rain and other weather conditions.
Talk with your preferred roofing services about performing any of these steps for you.