Roof cleaning

The Asphalt Roofing Manufacturers Association (ARMA) recommends using a 50/50 solution of household strength sodium hypochlorite (pool chlorine) and water to remove moss and algae.

[5] The addition of zinc strips near the roof's peak may reduce the regrowth of algae and moss.

One safe and effective means to clean a roof is an electric agricultural sprayer system, as originally developed in Florida, USA in the early 1990s.

ARMA discourages the use of a pressure washer, a flat-surface cleaner or any other mechanical device to clean a roof.

Safe, effective soft washing cannot be achieved with a pressure washer, as the Venturi device (downstreaming) cannot achieve sufficient strength of solution to kill the organisms, cleaning the roof.