ODA licensing is very important when choosing your contractor for treatment, along with the right conditions.

So we want to make sure you choose a contractor who is licensed and bonded with workers comp insurance if they have employees. Also, they will need to be licensed with the Oregon department of agriculture. The treatment option can help so that the moss does not return but you want the contractor to wait until optimal conditions. The conditions of the weather are very important because for one, you want the treatment to work so you waste your money. Second, the weather can dictate how much treatment will stay on the roof, and it could be dangerous to treat when its windy. Particle drift can be bad for the environment. We apply the application in the spring and fall when the moss spores are active and open. Moss is usually dormant during the winter and summer months so it may be a waste of treatment during those times. It couldn’t hurt, its just not optimal.