If you have black stains on your roof, you most likely have a build-up of algae. This algae is not dangerous or damaging in any way, but you may still want to remove it if you are concerned about the aesthetic qualities. Here is what you need to know.
Don't Wash it Yourself
The most important thing to understand when attempting to clear your roof of black stains and streaks is that you should not power-wash it off. Using a power-washer will take the stains off, but it will most likely damage your roof in the process. You should also consider not doing any part of this yourself. Roofing is dangerous, and if you make a mistake the costs will only increase. It is much better to have black stains on the roof than a broken leg.
Washing or Zinc?
There are two methods to removing black algae on your roof — washing it off with a chemical mixture diluted in water, or zinc strips. There are a variety of recipes available to make your own algae-killing mixture, along with an even larger variety of commercial products meant just for the black streaks. Whatever chemicals you choose, be aware that it will most certainly run off the roof and into your yard. The mixture may be safe for you to breathe in and touch, but most materials that kill algae will also kill your plant life.
Additionally, you can also apply zinc strips to your roof, or rather hire someone to do it for you. These zinc strips release zinc when it rains and allows it to flow down your roof and kill the algae present while preventing others. These strips are low maintenance and last for roughly five years, and they are effective against simple plant life first and foremost. This means any plants near your roof where water could run off are more likely to survive than a 5:1 water and bleach mixture.
Overall, there are a variety of options when choosing to remove black algae from your roof. You should consider using a roofing professional or contractor before you begin. Additionally, avoid using power washers, as they will damage your roof. Black algae can be removed with chemical mixtures diluted in water that you can either make yourself or find in stores. You can also choose to apply zinc strips to your roof that allow zinc to flow down the roof every time it rains. Finally, be aware of what option you choose, as your anti-algae form of defense will almost certainly affect your yard as well.
For more information, reach out to a local roofing contractor.
