What issues does moss cause on a roof?
Short answer. Moss on a roof causes leaks from water wicked under the shingles, lifted and unsealed shingles that blow off in storms, granule loss, rotting decking and fascia, clogged gutters, and a slippery, hazardous surface. It can also hurt resale and raise questions during insurance or home inspections.
Roof covering issues
- Lifted shingle edges and broken seal strips, making shingles vulnerable to wind.
- Granule loss under and around moss, exposing asphalt to UV.
- Accelerated aging on the shaded slope, so one side of the roof wears out before the other.
Water issues
- Leaks where moss wicks water past the shingle laps.
- Wet underlayment and decking, which can rot without any visible ceiling stain at first.
- Overflowing gutters clogged by moss debris, soaking fascia and soffits.
- Ice at the eaves on rare cold snaps in North Georgia, when wet moss freezes.
Safety and pest issues
- Mossy shingles are slick, even on dry days.
- Thick moss and debris give insects places to live, and clogged gutters breed mosquitoes.
- Birds and squirrels pull up moss looking for food, disturbing shingles further.
Money and paperwork issues
- Buyers' inspectors flag it, often leading to repair requests.
- Manufacturer warranties generally exclude damage from lack of maintenance.
- Insurers may view moss damage as wear and maintenance, not a covered sudden loss.
Fixing the root cause
Moss returns wherever shade, moisture and debris stay. Trim branches, clear the roof and gutters regularly, and consider zinc or copper strips. See moss and lichen on roofs, gutters and guards and the Georgia maintenance checklist.