September 20, 2026 · Job note
A house wash does not clean the roof
Black streaks on shingles are algae. They are treated at low pressure. They are not blasted off with the house.
People ask for the whole place to be washed. The house and the roof are two treatments. The mix is not the same strength, and a pressure tip does not go on architectural shingles.
Black streaks are algae. They hold moisture. A soft-wash treatment is meant to kill that growth so rain can rinse the dead film. Granules are the roof's skin. A wand will cut them.
If a quote is one number to wash everything with the same gun, ask what happens to the granules and what is kept off the plants. The honest answer is specific.
Gutters are separate again. Streaks down the siding are often the gutter, not the wall. Cleaning the wall and leaving the gutter just paints the streaks back.
The longer guide: Why a roof is not pressure washed
Related: House washing, Roof soft washing, Work gallery, Send photos.