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Gredo Goldenstein
11-05-2005, 4:08 PM
My wife and I were out for a walk today and on the way back to the house I noticed moss starting to grow on the North/NorthEast side of the roof. We moved-in in April. I put in soffit vents this summer and insulated the attic about a month ago. The attic should have more breathability than it's had since it was built 53 years ago. Now the roof is in dire need of replacement, I know that but no $$ until spring. Now, where did the moss come from?

Jason Roehl
11-05-2005, 4:35 PM
It came from the north side. :D What you can do to prevent it is to use copper flashing above it. I think there's enough acidity in the rain to react with the copper and make a compound that is toxic to the moss, which then washes down and prevents it from growing. As for now, if it's thick, scrape off what you can and bleach (~3% solution) the rest, then rinse well.

Joe Pelonio
11-05-2005, 4:44 PM
We're famous for our moss out here. Some houses in the neighborhood they have given up fighting it and have a good half inch in spots. Any moisture from dew or rain is going to encourage moss if the sun doesn't hit it. Here it's areas shaded by huge trees, and areas facing north where the sun never hits it. Lucky for me I do bonsais and harvest it, not so much from roofs but from the ground.

We have a ton of moss killers at all the home improvement stores, the copper trick works, and also some people swear by the Tide laundry detergent, just sprinkle it on the moss and the rain wets it and kills the moss. They say other brands don't work, just Tide.

Tim Sander
11-05-2005, 7:22 PM
We get tons of the stuff up here in Vancouver. I would have to scrap it off every year, and I don't think its any good for the roofing either. I've heard of a way and tried it and have not scraped for 2 years. Zinc sulphate works like a charm. You can get it in powder form from the hardware store (not the big boxes), it is safe and easy to apply. You mix 1 pound to one gallon of warm water and spray it on with a low pressure garden sprayer.

Steve Ash
11-05-2005, 7:27 PM
Zinc Strips......haven't used them in a few years but I would get them from the lumberyard. You put them under the next to last (top) row of shingles. Might be something newer/better now.