Moss is a collection of a bunch of smaller plants that have grown together. They thrive in shady locations. Moss may grow on parts of your roof, sidewalks or driveway that aren't directly exposed to the sun. If the moss continues to grow it can damage your roof or concrete. Kill it as soon as you see it.
Pour one bottle of bleach into a large bucket. The size of the bleach bottle doesn't matter because you are going to use your empty bleach bottle as your measuring instrument. Your bucket should be able to hold at least five gallons of liquid.
Fill the empty bleach bottle with water, then pour it into the large bucket. This gives you a 50/50 solution.
Mix the bleach and water together. Carefully pour some of it into a watering can, which is much easier to use when you are ready to apply the bleach/water solution to the moss.
Use the watering can to drench the moss with the bleach/water solution. Start at the top and work your way down. Once the moss is soaked, it should begin working in as little as four hours. You will notice the moss turning a yellow colour. Make sure that you don't allow the bleach/water solution to touch the grass because it will also kill the grass.
Clean the watering can in your bathtub after each use. Dish soap and water is all you need. Make sure you completely rinse out the bleach so that you can use the can for other things.
Use the bleach/water solution a second time on your roof or concrete, along with a scrub brush. This will remove any stains that still remain because of the moss.
Moss treated with bleach will die, but it can return later. Never use undiluted bleach on your roof. Make sure you wear waterproof gloves when you use the bleach. It can burn the skin.