Roof Cleaning For best results: Have me clean off the moss and then coat the roof with zinc sulphate monohydrate to kill the moss spores that cannot be seen, but will begin to grow and multiply immediately after cleaning. As you well know, roof moss is a real problem in the Pacific Northwest.  It roots into the shingles, drying them out, causing them to become brittle, and eventually to crack and leak.  Moss also grows along the edges of shingles, raising them and drying them out even more rapidly.   Any metal will kill moss, and I use zinc to kill roof moss.  But killing the moss does not remove it.  Even dead, it still lies there, holding moisture against the shingles, deteriorating them.  So I recommend cleaning the moss off first, and then coating the roof with zinc sulphate monohydrate to kill the moss spores which cannot be seen but which will begin to grow and multiply immediately after cleaning. My advice: have me clean the moss off your roof once and then recoat it with zinc every year. This mossy roof... ...looks brand new after cleaning and treating. After cleaning, I clean out the rain gutters... ...because they are full of removed moss. When proper equipment and technique are used,... ...more aggregate is lost from walking on it than from the cleaning process. This moss had been killed by the homeowner, but it still lies there, deteriorating the shingles. Now the roof has a chance. Cleaning not only extends the life of the roof,... Even really old roofs... ...it also restores the color of the shingles. ...can be cleaned when done right, and with the right equipment. Street appeal and... ...value are enhanced. “Healthy yards through knowledge and experience” STEVE MILLER Owner / Laborer Licensed, Bonded, Insured 360-258-6383 The best choice to call when you want: Hand thinned & shaped shrubs, hedges & trees Lawn maintenance including cut new edges; bark; aerate; dethatch; feed; treat pH & clay; insect, disease, & weed control Roof, concrete, deck & fence cleaning and treatment Retaining walls, fences, sheds & decks built Over-seeding and lawns installed Sprinkler systems designed, installed and maintained