Sound wind and estate shade on Greenwich roofs
Shoreline roofs take salt air and wind-driven rain from nor'easters and tropical storms, which push water under slate, cedar and flashing from angles ordinary rain never reaches and corrode exposed metal. The backcountry is heavily wooded, so roofs are shaded, moss and algae grow on north slopes and valleys fill with leaves. Steep pitches on the estates shed snow but build ice behind dormers and in valleys after a cold snap, and complex rooflines have many inside corners for it. Freeze and thaw works at copper and lead flashing on the older houses.

