Brian C. Jackson is a specialist in non-pressure / soft wash roof cleaning and he cleans the ugly black stains off of the roofs in Massachusetts. The town of North Chelmsford , Massachusetts 01863 is having this same problem with ugly black stains on the roof. This problem with black stains is an algae called gloeocapsa magma and this is not good for the roof and it needs to be cleaned. The ARMA (Asphalt Roofing Manufacturers Association) does not approve or recommend to clean a roof with a power washer or a pressure washer because of the damage that can be done to the roofing granules. The approved way of cleaning a roof is a non-pressure / soft wash application that will not damage the roof. To view some more information on roof cleaning or any of our exterior soft washing services just visit our web site @ www.jacksoncontracting.net . Or call Brian @ 603-401-8408 to get a free estimate.