Moss Treatment

• Zinc sulfate strips are hailed by environmental groups as being a nature-friendly way of treating your composite shingles for moss -- whether it's already grown or may grow in the future. Nailed along roof peaks, these common deterrents are used to treat new and old composite shingles for moss.
  
  

How It Works

• When it rains, the water slowly dissolves zinc sulfide that treats the water draining from the roof, lightly coating the roof with a thin layer of a known moss deterrent. Other moss treatments also contain bleach or copper. The concentration of zinc sulfide is often increased when used by roof cleaners faced with composite shingles already coated in moss.
  
  

The Wrong Approach

• Pressure-washing or brushing a composite shingle roof will quicken the crumbling of the shingles' granules and possibly expose nails to sunlight and then, rust. Sprinkling zinc shingle cleaner on areas of moss works better than scrubbing at problem areas, according to roof cleaners Waterworks NW.