Quick answer
What matters first
Document when the symptom appears, where staining begins, the skylight age and type, previous sealant or roof work, and whether condensation occurs in cold weather. The exterior inspection should review the unit, factory or site-built flashing, underlayment integration, surrounding roofing, and the upslope water path.
Start with the timing and pattern indoors
Note whether moisture appears during wind-driven rain, prolonged rainfall, snowmelt, or cold dry weather. Photograph the first visible point, staining direction, bubbling paint, trim condition, and any moisture on the glass or frame.
These observations do not replace an inspection, but they help distinguish exterior water entry from condensation or a problem that begins farther upslope.
Inspect the whole opening, not only the glass
The exterior review should identify the skylight type, curb or deck mounting, visible age and condition, flashing configuration, underlayment integration, fasteners, sealants, nearby shingles or membrane, and any debris or drainage restriction above the unit.
Repeated surface caulking can temporarily change the symptom without proving the assembly is integrated correctly. Ask the proposal to explain what will be opened and rebuilt rather than relying on a generic promise to reseal the perimeter.
- Glass, frame, gaskets, and visible drainage paths
- Head, side, and sill flashing components
- Roof covering and underlayment around the opening
- Upslope valleys, walls, penetrations, or transitions
- Interior shaft insulation, air sealing, and condensation clues
Match the repair to the roof system
A skylight in an asphalt-shingle roof, low-slope membrane, metal roof, or older layered assembly requires a compatible flashing and tie-in approach. The proposal should name the work area and state whether surrounding material will be removed and replaced.
If the roof is near replacement age, compare the risk of repairing the current opening now with replacing or reflashing it as part of the larger roof project.
Write the replacement scope before the roof is opened
When replacement is recommended, compare the exact unit, size, mounting method, flashing system, interior finish responsibility, disposal, weather protection, and workmanship coverage.
If concealed deck or framing damage is possible, require a unit price or written change-order process and photographic documentation before additional billable work proceeds.
Homeowner checklist
Skylight leak intake checklist
- Skylight location, type, size, and approximate age
- Weather conditions that trigger the symptom
- First visible stain or moisture location indoors
- Condensation on glass, frame, or shaft noted separately
- Prior roof, flashing, skylight, or sealant work
- Surrounding roof material and approximate roof age
- Interior trim and finish responsibility in writing
- Repair or replacement warranty boundary in writing
Questions homeowners ask
Clear answers before the next step
Does water beside a skylight mean the unit must be replaced?
No. The unit is one possible source, but flashing, roofing, underlayment, an upslope detail, and condensation can create similar symptoms. The condition and integration should be inspected before deciding.
Can sealant alone be a permanent skylight repair?
That depends on the verified defect and the intended repair method. Surface sealant should not substitute for rebuilding failed flashing or correcting an improperly integrated assembly when those are the actual conditions.
Should an older skylight be replaced during roof replacement?
Ask for a condition-based recommendation that considers unit age, compatibility, flashing access, warranty, and the cost and disruption of reopening a new roof later. The decision is property-specific.
Official resources
Requirements can change. Confirm current, property-specific information with the responsible agency.