How do I clean the Moss off my roof?
PABCO® recommends cleaning moss from your roof by killing the moss with an application of a 50:50 mix of liquid chlorine bleach and water. This is sprayed onto the surface of the moss with a low pressure sprayer, like a garden weed sprayer. Allow the solution to dwell on the surface (15 to 20 minutes) and then rinse thoroughly with low pressure water. Extended dwell times may be necessary to kill the moss, however avoid letting the solution dry completely as this may prevent complete rinsing. After the moss is dead, it will weather off.
Do not use abrasive cleaning methods such as pressure washing or the use of a brush or broom.
See the PABCO® Technical Bulletin on Recommended Maintenance Practices for additional details and related information.