....Use a power washer and a mixture of DILUTED Muriatic Acid . Mix 1/2 cup of it to one gallon of Hot water for each washing .
Be careful of not violating your roof shingle warranty. Muriatic acid and power washing will also remove the protective granules from the shingles leaving you basically asphalted tar paper.
A pressure washer could easily damage roof shingles and the mineral content of a composition roof could easily react with the muriatic acid and alter the roof color not to mention would destroy any painted surface it gets on. I'd use a very simply 25% bleach solution in water. Spray it on, keep it wet and let it sit a while then simply hose it off. If a 25% solution doesn't work move up to a 50% solution. A gallon of bleach is cheap comparatively to a gallon of acid not to mention a lot less hazardous and no need for any equipment other than a pump up sprayer and a water hose with sprayer.
Completely agree Dennis!
Hmmmm. It would seem I have a hacker. :( I know all about ' muriatic acid,' and wouldnt recommend it for cleaning shingles.....not to mention I seldom reply in that ' manner' when posting. I am a bit verbose . ( so I have been told. ) Off to change password and see if I can find out whats going on. :(
Just wet the area with moss and then sprinkle baking soda. The end. The moss should die within a couple of days.
It's not toxic and you don't have to use any special equipment. 😃
Wet and Forget....get it on Amazon....had lichens on roof...easy and it works.
There is a video on YouTube. I had very bad moss on my shed roof. Use a 3 gallon bleach sprayer. Mix 2 gallons water with 1 gallon of heavy duty bleach (I believe 12.5% or 14%), not the store bleach. You should be able to find it at a pool supply store. Add 4 tablespoons of dawn dish detergent. The dish detergent helps it adhere to the roof. Cover any plants or grass below so it won't be harmed. Spray on and you will soon notice the moss dying and turning yellow. Mother nature will wash it away in a few months if it's really bad. Also, if you aren't afraid to climb onto the roof, you can use a stiff non-handled broom to brush DOWN on the shingles lightly. I highly recommend you watch the video first.