Shingle Roof Cleaning - Black Algae

I did this for my parents house about three years ago. Still no algae.

1 part bleach. 1 part water.
Spray on roof with a garden sprayer
Wait about 15 minutes
Spray off with a garden hose

Just work a section at time. If the bleach mixture starts to dry off before the 15 minutes is up, then work a smaller section. And you must spray the bleach mixture on a dry roof.

Note: You will have to get the roof wet enough with the bleach mixture. A little misting won't be enough to work.

Do it in the morning or late afternoon. If that roof is hot, that bleach mixture will steam up or vaporize and get in your lungs.

I was able to spray from a ladder at the base of the roof. So the sprayer needs to be strong enough to reach the top of the roof if you do it that way. Otherwise you will have to get on the roof, which I would NOT recommend unless you have someone on the ground to help you refill your sprayer, hose off the roof and hose down any plants or trees that the bleach might get on.

I did it with a shitty hand held pressure sprayer. frick that. Go to harbor Freight and get one of these:

Mix Jomax with the bleach

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Shingle Roof Cleaning - Black Algae by skullopener

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you can spray it with either bleach or with roundup, if you want something less toxic. only trouble is, it will kill plants around your house unless you can wash it off of them pretty quickly.

2nd for jomax and adding a little dawn to the mixture will help keep it from drying out so fast. I think Bozeman sells a special surfactant to to add to your mix to help with dwell time and to wash off windows with no residue or streaking.

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reliable cleaner

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Hail