The hole in the roof you meant to put there
Skylights earn their keep in a gray climate, and they're also one of the most common leak points on any roof in the county. The frame, glazing seal, and flashing each fail differently, and each has a different fix.
What usually goes wrong?
- Failed flashing, the most common leak source; the skylight is fine, the seal around it isn't
- Fogged double-pane glazing, the glass seal failed; cosmetic at first, but the insulating value is gone
- Cracked or crazed domes, older acrylic units get brittle with age and crack under impact or UV fatigue
- Old curb-mount units on a new roof, a skylight outliving its flashing detail is a leak waiting on a calendar
Repair or replace?
Reflashing a sound unit is a real repair and the right one when the glazing and frame are solid. Fogged glass, brittle domes, and twenty-year-old units on a roof being replaced anyway argue for replacement with a modern low-e, flashing-kit unit. Newer skylights integrate with the roof system in a way the old curb-and-caulk jobs never did.
On a reroof, always ask
If the roof is coming off and the skylights are old, replacing them during the re-roof is far cheaper than reflashing around them now and replacing them later. The roofer who calls should raise this if it applies to your house.
What should a quote include?
Whether the unit or the flashing is the failure, the replacement unit type if it's coming out, curb and flashing scope, interior finish work at the light well if the leak stained drywall, and whether it can wait for a dry spell or needs a temporary seal now.
