Copper Sulfate Roof Treatments

Copper Sulfate Mix and Application

• Apply copper sulfate at a rate of about 1/4 to 1/2 ounces per 10 gallons of water. Use a hand sprayer to apply the mix to soak the surface of the shingles. Apply the mix when dry weather is anticipated for several days. Apply copper sulfate to wood, fiberglass or asphalt shingles that show moss growth. Apply during active growth periods of the moss, which usually occurs in the spring through fall of the year.

Copper Sulfate Safety

• Copper sulfate is corrosive to metal items such as eave troughs or downspouts. Wash the mix off these metal surfaces as soon as possible after application. Prevent runoff from the copper sulfate from contacting landscape plants and lawn grass below the roof.

Other Moss Prevention Mixes

• Zinc chloride, zinc sulfate and table salts all kill moss and prevent its growth. Each of the chemicals utilizes its own mix formula and is applied according to manufacturer's instructions. All are corrosive to metals and harmful to landscape plants. Always use caution when applying any moss control chemical to the roof.

Physical Moss Prevention

• Proper physical maintenance of the roof reduces moss growth and may eliminate the use of chemicals such as copper sulfate. Trim overhanging tree branches near the roof to help air circulation that dries the shingles. Sweep or wash away any buildup of leaves, branches or other debris on the roof. These materials hold moisture against the shingles, providing advantageous growing conditions for moss. Monitor north and east roof exposures. These areas receive the most shade and will retain moisture the longest, allowing moss to grow.