PREVENTING ROOF MOSS If you want to be more proac- tive, there are some additional things you can do to discourage future growth of moss and algae.
1. Trim tree branches back to allow more sunlight to reach the roof
2. Reduce debris accumulation on your roof, which is often a problem with low-pitch roofs, because leaves and branches tend not to blow off. Use a leaf blower to clean the roof, directing the airflow down the slope.
3. Keep gutters clean to pro- mote water drainage.
4. Do not allow gutters from an upper roof to drain directly on a
lower roof. Extend the downspout from the upper roof into the lower gutter.
Add zinc or copper strips to prevent both algae and moss on shingle roofs, or apply asphalt shingles that incorporate algae- resistant copper granules.
Editor’s Note: Robb Robillard is a professional remodeling contractor. Visit his blog at www.aconcordcarpenter.com.
Rinise thoroughly with water, spraying in the direction of the roof’s downward slope. Reapplication of the bleach may be required for roofs with heavy mold problems.
Before and after.