pacific

What’s That Beautiful Green Stuff on my Roof?

In the wet Northwest, we sometimes get things that other parts of the country seldom see.  In this case, the beautiful green stuff is moss; and it is not beautiful on a roof.  Moss growth on a roof causes several problems and is considered a “conducive condition” for wood destroying organisms.  Moss growth can cause roofing nails to lift, hold moisture against the roof and ultimately destroy the shingles.  In the early stages, it is easy to deal with.  A little zinc powder strewn above the growth during the growing season (moss grows in the winter when it is wet) can kill the moss. If it gets a little farther along it can be mechanically removed.  This does not  mean pressure washing.  Pressure washing dramatically shortens the life of a roof.  The photos below show moss at a stage that is almost beyond control.  The whole point of this is to control it in the earliest stages.