Why do Cape Coral roofs get black streaks and green growth?
The climate does it. Heat, humidity and a long wet season give algae what it needs. Roofs that face north, sit under trees or stay shaded in the afternoon grow it first. Homes near canals and open water get extra moisture in the air, which keeps the roof damp longer after a storm.
What we see on different roofs
- Asphalt shingles: dark vertical streaks and sometimes moss near the edges.
- Concrete and clay tile: black, green or gray growth that settles in the low spots and on the shaded slope.
- Metal roofs: mildew along the seams and a dull film.
Growth that has been there for a long time may leave light staining behind, even after cleaning. We tell you what to expect before we start.

