A to Z Softwash is the most experienced roof cleaning company servicing Cape Cod, Southern mass, Rhode island, Nantucket and Martha's Vineyard. All roof are cleaned without using a pressure washer! Growths such as lichen, moss, fungi, bacteria and algae are on most roofs these days. The first growth that shows its ugly head is typically bacteria (black streaks). Once this growths takes hold it will colonize and spread rapidly. Just like every other living thing, as it eats it excretes waste. This waste product is a food for other things..... such as moss and lichen! That is why when you see lichen in Southern Mass and Cape Cod it is usually growing right on top of the bacteria. It's an Algae party and your roof was invited. The only appropriate course of action is to hire your local roof cleaning company in Massachusetts that uses the proper methods. Which is of course a non pressure cleaning using the detergents that the shingle manufacturers recommend. Pressure washing, roof scrubbing and low pressure are terms and things you need to watch out for as those methods will damage your shingles. Another tip would be for you to ask for a copy of there insurance policy to be sure that you will be covered if god forbid something does go wrong. Asphalt shingles and cedar shingle roofs are going to have a short lifespan if they aren't clean, this is a fact. Insurance companies are even making people clean their roofs more and more. They are doing this because algae is costing them money! I haven't even mentioned the fact that dirty roofs are (forgive me for saying it) ugly. Take a look at some of our work below to see for yourself.