To apply Lilly Miller Moss-out to your roof, follow these steps: Mix one part concentrate with 19 parts water (6.8 oz in 1 gallon of water). Thoroughly wet the moss with water before applying the solution. Use a garden sprayer to apply the mixed solution to the moss-covered areas. Make sure to cover all affected areas. Let the solution sit for a few hours to effectively kill the moss. After the moss has died, rinse the roof thoroughly to remove any residue.