The streaks start on the shady slope and run down with the rain. Pressure scatters them and strips the granules; a soft wash kills them where they grow.
100
PSI on every roof
0
Steps on clay or concrete tile
Before: the north slope
Asphalt shingle
Soft wash, from the ladder
Clay and concrete tile
Soft wash, from a lift
Metal
Low-pressure rinse
Leaves and grit cleared by hand
Downspouts flushed until they run clear
Flow checked with a hose
Black tiger stripes lifted from the face
Brackets and seams checked
Fascia rinsed on the way down
From $149 with a roof wash
Most shingle makers recommend a low-pressure clean. We follow that, and never use full pressure.
Most fade the same day. The last shadows wash away with the next few rains.
Every two to three years in our climate, sooner under trees.
On shingle, carefully. On tile, never: we work from a ladder or a lift.
