Moss is not a normal and acceptable part of aging

Here in the damp Pacific Northwest, it seems that homeowners and even some realtors look upon heavy moss growth on the roof of a home as a normal part of the roof's aging process, as if that was factored in by manufacturers. Granted, without care and maintenance, it will be present in many cases but moss should be treated, as needed, and kept off of roofs. When manufacturers state warranties, they are not considering that a few years into it, moss will be growing. That is NOT a planned on or acceptable part of the roof aging. There are a number of moss treatments for roofs. They are applied by sprayers or watering cans and if the moss is caught as it is first forming, it will not even need swept off after it dies. If it is heavy growth, then it likely will need cleaned after the chemical kills it. From my experience, I have found that the zinc strips they install at the ridge serve no function that is useful. They do often leave nail entry holes in the roof when the strip falls off. Another factor is this: When moss is really heavy, such as in the picture below from one of my inspections, it is possible the roof will leak when the moss is removed. The moss might be the only thing holding together but, in so doing, the roofing materials are being seriously exposed to constant moisture and neither wood nor comp roofing is designed for that. By the way, with the roof below (and one becomes used to this) the owner saw no problem and said the roof was a 30 year roof and had at least another ten years in it.

Thanks for looking,

Steven L. Smith

www.kingofthehouse.com