Aside from the challenges of working from a ladder, killing roof moss is fairly simple. You can use items from your laundry room, like detergent, to get the job done.
Laundry detergents contain compounds called surfactants, which help the chemicals in the detergents penetrate stains and organic materials like moss. This deep penetration helps washing powder kill moss growing on your roof.
To kill roof moss, add 1 cup of powdered washing powder and 1 cup of bleach to 5 gallons of water. Wet the moss with the solution, and let it sit for 10 minutes. Then rinse away the dead moss and the solution with water.
If roof moss is a recurring problem for your home, you can use washing powder to kill and remove it every year. You can prevent roof mould and other fungi from growing by laying copper or zinc strips on your roof. They release ions that form a protective coating on your roof, preventing mould and other fungi from growing there.