Moss or mold on your roof may look harmless at first, but it’s actually a sign of trouble. Moss traps moisture, which slowly eats away at roofing materials. Algae and mold also weaken shingles and create unattractive dark streaks that reduce your home’s curb appeal. In London’s damp climate, this problem is very common. Professional roof cleaning and treatment are the best solutions to stop moss from spreading and extend the life of your roof.