Moss growing on your roof is a silent destroyer. Moss is a living plant that feeds on asphalt roofing material and can begin to put holes in your roof over time. Even a brand new roof is at risk of being damaged by growing moss. There are a few different strategies to use when removing moss, and which one you use really depends on your personal preference.
Bleach and Water
Bleach can be used to help kill and remove moss if it is diluted by water first. You can mix up a batch of half bleach and half water to apply directly to the moss on your roof. To avoid bleaching the shingles try and do this on an overcast day to prevent direct sunlight from mixing with the bleach. On the ground level, spray the grass and any foliage you have beneath your roof with water to help protect them from the bleach debris. Back to the roof: Let the bleach and water solution sit for about a half hour and then brush it off gently with a wire brush. Hose down the roof when you are done and that should remove the moss.
Many people use pressured water to remove the moss from a roof, but if it is not done properly then you could cause water damage to your home. Set the tip of the water pressure hose at an angle so that it is performing a sweeping cleaning motion as opposed to applying water straight down on roof. According to Askthebuilder.com, you should use no more than 1134 Kilogram per square inch of pressure. Apply the water in a sweeping motion and allow the natural pitch of the roof to carry the water and moss down to the gutter and out the downspout.
No Chemicals or Water
Some people are hesitant to use chemicals or pressured water on their roof for moss removal, and there is a strategy they can use as well. Use your garden hose to gently apply water to the area affected by moss. Then climb up there, safely of course, and begin removing the moss with a stiff brush. In some cases the moss may be so deep into the asphalt shingles that you may have to remove the shingles and replace them. This process can take a little while longer, but there are no chemicals to use and no threat of water damage to the house from a pressured water gun.
There are a couple of things you can do to help prevent moss from accumulating on your roof. Remove any tree limbs or other foliage that hangs over your roof or lays on your roof. The shade and moisture promotes moss growth. Each spring treat your roof with an environmentally friendly moss prevention chemical that will discourage moss growth. The best way to make sure you do not have moss problems again is to have your roof redone with ceramic shingles or aluminium roofing material instead of asphalt.