Roof soft washing that kills the algae, not the shingle
Those black streaks are a living organism, not dirt, so the job is to kill it rather than blast it off. Soft washing applies a cleaning solution at roughly garden-hose pressure, lets it work, then rinses — no pressure on the shingle, no granule loss, and no immediate regrowth.
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The problem this solves
Black streaks running down a shingle roof, dark patches on the north slope, or green growth spreading under the tree line.
What the black streaks actually are
Gloeocapsa magma, an algae that feeds on the limestone filler in asphalt shingles and spreads downhill with the runoff. That is why the streaks always run vertically and always start near the ridge. Our humidity and heavy shade make North Florida close to ideal growing conditions for it.
Why pressure washing a roof is the wrong tool
Pressure strips the granules that shield the asphalt from ultraviolet light, and those granules are the shingle's service life. It also drives water under the shingle edge. A pressure-washed roof looks clean for a season and has years taken off it, which is a trade nobody agrees to knowingly.
How soft washing works instead
A cleaning solution is applied at roughly garden-hose pressure and given time to kill the organism at the root. The roof is then rinsed gently. Because the algae is dead rather than displaced, it does not simply regrow from whatever was left behind, and that is the difference that lasts.
What we protect before we start
Plants and turf below the roofline get wet down before, during and after, and downspout discharge is directed away from the beds. Runoff is the part of soft washing that goes wrong when it is rushed, so it gets planned before anything is mixed rather than managed once it is already running.
How long the result holds here
Typically two to four years, depending on shade and tree cover. A roof under a closed live-oak canopy will streak again sooner than one in full sun, because the organism needs moisture and a canopy keeps the slope damp. Clearing overhanging limbs extends the result more than any product does.
QUESTIONS ABOUT THIS SERVICE
Roof soft washing questions
Does soft washing damage shingles?
No. The pressure is comparable to a garden hose, so nothing is being driven at the shingle surface or under its edges. The cleaning happens chemically rather than mechanically, which is the entire reason the method exists for roofs.
Will the black streaks come back?
Eventually, because the spores are airborne and nobody can stop them landing. What soft washing prevents is regrowth from organism surviving on the roof itself. Expect two to four years in Tallahassee, and less under heavy shade.
Is the cleaning solution safe for my plants?
It is safe when the runoff is managed, and managing it is our job rather than yours. Beds and turf are saturated with water before we begin so nothing concentrates in the soil, then rinsed again afterwards. Sensitive specimen plants get covered.
Can you soft wash a metal or tile roof?
Yes, and the method suits them well, since neither should ever see high pressure. The solution and dwell time change with the material and with any coating already on it, so we look at the roof before quoting rather than pricing off square footage alone.
Get roof soft washing scoped properly.
We inspect before we quote, so the price answers a defect we can show you rather than a guess.