Roof moss contamination by neighbors mossy roof

I had an interesting call from the owner of one of the asphalt roof houses cleaned recently with Roof Wash. Her neighbor's roof is heavily covered with roof moss and she was wondering if she should pressure him to clean it as his moss could hasten the spread of moss to her newly cleaned surface.

My answer was as follows..."I hate to say it but the beautiful oceanside/mountain environment (Lion's Bay, British Columbia) you live in is "moss heaven". The culprit is something called "Goeocapsa Magma", that can spread from one infected roof to another by the release of airborne spores into the wind, allowing this hardy moss to rapidly tranfer to your roof.

The problem is, in Lion's Bay there are so many other sources of moss around your house, trees, ground cover, shady roofs, indeed, like the whole Pacific Northwest, that blaming it soley on your neighbor's roof is futile.

There is a remedy for prevention however. You have taken the first step by cleaning all the fallen pine needles and tree debris off the shingles. Then when you laid up a layer of Roof Wash, you have effectively stopped any current damage to your roof by a moss and algae buildup. The Roof Wash has effectively distroyed the roots and spores of the moss and algae present on the asphalt, and will prevent regrowth for some months ahead.

Considering the environment where you live, you may need to re spray the roof with Roof Wash more often than some of the other houses in more open areas. I would suggest that if you make a spring and fall Roof Wash treatment as part of your normal house maintenance, there will no danger of long term damage to the shingles from moss and algae."