Will moss on my roof damage it, and how do I check for damage?
Short answer. Moss can damage a roof if it is left in place, mainly by lifting shingle edges and keeping the roof wet enough to rot decking. Once the moss is killed and removed, check for curled or lifted shingles, bare spots, soft decking and attic stains to see whether you need a repair or just prevention.
Checking after the moss is gone
- From the ground: lifted or curled shingle edges, missing tabs, and light colored patches where granules came off with the moss.
- In the gutters: heavy granule buildup after removal.
- In the attic: water stains, dark spots on the underside of the decking, or damp insulation under the mossy area.
- Underfoot, if a roofer walks it: any soft or spongy feel in the decking.
Repair or replace?
- Small area, shingles intact: prevention only, with zinc or copper strips and trimming.
- Some lifted or broken shingles: a repair that replaces or reseals those shingles.
- Soft decking or widespread damage on an older roof: replacement is often the better value, especially past 15 to 20 years.
Will insurance pay?
Usually not. Homeowners policies cover sudden events like wind and hail, and they generally exclude wear, neglect and gradual deterioration. Moss damage falls in that category. Interior water damage from a sudden leak is a policy specific question; read your policy.
Prevent a repeat
Moss returns wherever shade and debris stay. Trim branches, keep valleys clear, and keep gutters flowing. See moss and lichen on roofs and signs you need a new roof.