Why is my roof leaking water, and what damage can it cause?
Short answer. Roofs leak water when part of the system fails, most often a pipe boot, flashing, damaged shingles or a clogged valley or gutter, and even a small leak causes more damage than it seems. Over time it can rot decking and rafters, ruin insulation, stain and weaken ceilings, corrode nails and electrical boxes, and feed mold in a humid Georgia attic.
How the damage progresses
- Days: wet insulation loses much of its value, drywall stains, and mold can start on materials that stay wet longer than 24 to 48 hours.
- Weeks: decking around the entry darkens and softens, nails rust, and ceiling paint bubbles.
- Months: OSB swells and delaminates, rafters and wall plates begin to rot, mildew spreads on the underside of the decking, and wet wood attracts carpenter ants and termites.
- Years: sagging decking, structural rot at the walls, and damaged wiring and ductwork.
Why slow leaks are the worst
A dramatic drip gets fixed the same week. A slow leak that only wets the decking can run for years, unseen until a ceiling stains or the roof feels soft underfoot. A quick attic check with a flashlight once or twice a year catches most of them.
The insurance angle
Policies generally cover sudden damage from a covered event like a storm, but often exclude damage from long-term leaks, wear and mold that developed over time. Fixing leaks promptly and keeping records protects you. See interior water damage coverage.
What to do
- Find and fix the source.
- Dry or replace wet insulation and drywall.
- Probe the decking around the entry point for soft wood.
- Have an electrician check any wet boxes or fixtures.
See common leak causes and OSB vs plywood decking.