The black streaksare alive.

Those dark runs down your roof aren’t dirt, and they aren’t “just age.” They’re colonies of roof algae — a living organism that feeds on the mineral filler inside shingles and tile. It spreads where the roof stays damp longest: the north face, the shaded runs, under overhanging trees.

That’s why it comes back after pressure washing. Blasting shears off the visible layer and leaves the roots in the surface. The colony regrows from what’s left — usually within a season or two — and the pressure that removed it also stripped granules, opened tile pores, and shortened the roof’s life.

Kill what pressure washing leaves behind — that’s the entire idea, and it’s on our homepage for a reason.

The fix is chemistry, then patience.

A soft wash puts a soap-based solution on the surface at low pressure — roof-safe, section by section — and lets it work. The solution kills the organism at the root, growth and all, and then rinses away. Nothing left alive means nothing regrowing, which is why a soft-washed roof stays clean far longer than a blasted one.

Your landscaping is part of the plan, not an afterthought: beds get pre-soaked and covered before we start, and everything is neutralized and rinsed after.