Skylight leak repair starts with where the water really enters

What is skylight leak repair?

Skylight leak repair is the job of stopping active water intrusion at or near a skylight - after proving whether water enters at the flashing and curb, through the glazing unit, from condensation, or from a roof defect that only appears at the skylight opening. Caulk on the glass is rarely the durable answer. The durable answer is the detail that actually failed, sometimes including roof work beyond the skylight brand.

Signs you need skylight leak repair

• Active dripping or staining on the drywall well below a skylight after rain
• Water trails on the shaft walls only during wind-driven storms
• Wet insulation around the curb you can see from the attic
• A recent roof or skylight “reseal” that did not change the leak pattern
• Fog between panes plus separate drip stains - two problems, not one
• Leak timing that matches ice dams or melting snow at the curb in cold climates
• Stains appear only after wind-driven rain from one direction
• Caulk was added repeatedly and the leak still returns
• You see daylight or damp at the flashing step, not only on the glass

Seeing something not on this list? Browse skylights problems by symptom →

How skylight leak repair actually works

1. 1

   Reproduce the conditions and map the wet path

   Interior stains show where water leaves the assembly, not always where it enters. Attic access, moisture meters and controlled water testing (when safe) separate curb leaks from glass and from upslope roof issues.

   Watch forA bid that says “reseal skylight” without attic photos or a source hypothesis. That is hope in a caulk tube.

2. 2

   Temporary dry-in if contents are at risk

   Tarping, interior containment and protecting finishes may come before perfect permanent work when storms are ongoing. Temporary is not the repair - label it as such.

   Watch forA temporary tarp sold as a permanent flashing fix. Schedule the real detail.

3. 3

   Flashing and curb repairs when that is the path

   Step flashing, counterflashing, curb height and underlayment transitions are common failure points - especially after a reroof that treated the skylight as an obstacle. Repair may mean reflashing integrated with surrounding shingles or membrane.

   Watch forSurface silicone over failed step flashing. Water will go behind it.

4. 4

   Glazing and frame failures

   Broken seals, cracked lenses and failed gaskets need unit or glass work, not roofing tar. Condensation that looks like a leak needs ventilation and humidity conversation, not necessarily exterior tear-off.

   Watch forRoofers quoting glass seal failures they cannot warranty. Right trade, right part.

5. 5

   Replace when the unit or installation is spent

   Rotten curbs, obsolete units without parts, or repeated leaks after proper diagnosis push toward replacement. Leak repair should not become a multi-year caulk subscription on a doomed frame.

   Watch forEndless service calls that never open the roof. Cost the replacement path honestly.

6. 6

   Separate glass failure from flashing failure

   Condensation, failed seals in insulated glass, and true weather leaks from curb flashing are different repairs. Treating everything with more roof caulk is how leaks migrate and decks rot.

   Watch forTubes of sealant as the only tool on a flashing problem. Flashing is metal and membrane work, not a caulk sculpture.

7. 7

   Trace water path on a controlled wet test when safe

   A careful hose test from low to high, or inspection after a documented rain, finds entry order. Interior stains are often distant from the entry point on the roof plane.

   Watch forHigh-pressure spraying that forces water into places rain never reaches, creating false positives.

What does skylight leak repair cost?

Skylight leak repairs range from modest flashing work to full unit replacement with roof integration. Diagnosis time is part of the value - a cheap reseal that misses the source costs more than a thorough first visit. Surrounding roof repairs can dominate when upslope defects feed the opening.

See the full skylight leak repair cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →