Why are there black streaks on my roof?

Black streaks on your roof are caused by a bacterium called Gloeocapsa Magma, which feeds on the limestone granules in asphalt shingles. This bacterium, along with moss and lichen, thrives in humid climates like Montreal's North Shore. Besides the unsightly appearance, these organisms degrade your shingles, reduce their lifespan and can cause leaks. Aqua-Net's soft roof washing eliminates these organisms at the root with a biocidal treatment, without using high pressure that would damage your shingles.