Moss on a 3 tab asphalt roof

[Patrick Pisani]

HI Guys
A friend asked what he can use to remove moss that is growing on his 3 tab asphalt roof. I was thinking about some type of cleaner or degreaser. Any ideas?
THANK AGAIN
PAT PISANI

[Jim Luttrall]

Don't use a pressure washer.
Use a chemical product designed for the task, but I don't have a brand name for you.
Take a look here:
Roof Cleaning Chemicals and Products Guide (http://www.roofcleaningchemicals.com/)

[Raymond Wand]

Roof Moss (http://www.pesticide.org/RoofMoss.html)

[David McGuire]

Out of curiosity what is the source of shading on that side of the roof? Tree, other structure or what? He can remove the moss, but if he doesn't somehow increase the amount of sunlight and air flow on that part of the roof, it will come back at some point in time.

Just make sure he heeds the advice no matter what he does and doesn't use a pressure washer. That is, unless he has money and can afford a new roof.

[Matt Fellman]

Out of curiosity what is the source of shading on that side of the roof? Tree, other structure or what? He can remove the moss, but if he doesn't somehow increase the amount of sunlight and air flow on that part of the roof, it will come back at some point in time.

Just make sure he heeds the advice no matter what he does and doesn't use a pressure washer. That is, unless he has money and can afford a new roof.

Or, if it's like the houses here in Oregon he'd have to tip it on its side (towards the sun) to keep it from growing :)

We get A LOT of moss around here. I personally use a light solution of Roundup or similar weed killer. By far, prevention is the best avenue. Once it accumulates I think just treating it and waiting for it to die is the best thing to do. Maybe a light brushing with a broom but certinaly no pressure washer or wire brush. Once it dies it will usually just wash off the roof during a heavy rain.

[Patrick Pisani]

thanks for the quick answers guys, he just had a tree removed and wanted to clean the roof.
THANKS AGAIN

[Jim Hintz]

We get lots of moss here in Washington State too. Lillly-Miller "MOSS-OUT" works great as does "TIDE w/Bleach." Once the Moss turns black / is dead, I use a Corn Broom and sweep the roof sideways - going from gable to gable, not top to bottom - from ridge to gutter, that way the bristles remove the moss more thoroughly. Zinc Strips are old school technology, do not work well, and are not worth the money IMO.

[Michael Farha]

After removal, you can prevent further growth by laying a copper wire across the roof.