Those black streaks on the roof are not dirt

Shaded architectural shingles in West Georgia grow algae. Pressure is how a roof gets shorter.

The dark runs down a roof, especially the north slope and anything under pines, are almost always algae. Asphalt shingles hold moisture just enough for it. It is cosmetic until it isn’t — a colony spreads, and a homeowner eventually lets someone ‘clean’ it with a pressure washer.

Granules are the roof. Knock them off and you have cleaned the shingle into an earlier replacement. A roof soft wash is a treatment that kills the growth and lets weather finish the release. It will not look like a new roof the hour we leave. It will look even, and it will not be shaved.

If the shingles are already curling, cracked, or bald, washing is the wrong spend. We will say that. A pretty streak treatment on a failed roof is a waste of a listing photo and a waste of the fee.

Pine Mountain and the lake coves see this sooner than a new Newnan subdivision in full sun. Shade is the whole story. If the house is under oaks, plan on the roof being part of the conversation even when you called about the driveway.