Brian C. Jackson is a roof cleaner that cleans roofs with moss , lichen and black staining. The ugly black stains that is on the roofs in Fremont, New Hampshire 03044 is called Gloeocapsa Magma and it is an algae. This algae feeds on the roof and will degrade the roof over time and the roof will then need to be replaced earlier than expected. The only way a roof should be cleaned is with a safe non pressure / soft wash application that will not damage the roof or even possibly void the warranty. The ARMA (Asphalt Roofing Manufacturers Association) does not recommend or approve the use of a pressure washer or power washer because of the damage that can be done to the granules from a high powered machine. To talk to Brian call @ (603)401-8408 or visit www.jacksoncontracting.net for more info on roof cleaning or all of the exterior soft washing services we offer.