Apply on a damp roof with a low-pressure sprayer.
Put 2 lbs. of zinc sulphate into 5 gallons of hot water.
This will cover 500 square feet.
For best results put zinc sulphate on the roof when 2 to 3 sunny days are forecast.
(Temperatures outside should be 50 degrees or warmer)
Zinc Sulphate is available at most farm feed stores such as Buckerfields.
Please remember when working with ladders, height, and chemicals safety is the priority if the day. Safety harnesses are available at many local hardware stores. Surfaces may become slippery upon application. Please be reminded when using this solution with different materials apply on a small area to test for any discoloration. This recipe will only kill the moss and reapplication may be required upto 2-3 times per year.