Why Do Roof Shingles Turn Green? Causes and Safe Fixes
Roof shingles turn green primarily because moisture-loving organisms colonize the surface, especially cyanobacteria that create green or black stains, moss, and lichen. Shade, north-facing slopes, trapped leaves, humid air, poor drainage, and roof leaks increase the time shingles stay damp. Green discoloration can be cosmetic, but moss and lichen may dislodge granules and damage aging […]