Why skylights leak and how Roofers diagnose them
Skylight leaks can come from failed glazing seals, curb or flashing defects, condensation or roofing higher on the slope. Diagnosis treats the unit and surrounding roof as one opening. Underlayment and step flashing direct water even when the visible sealant looks intact.
Weather pattern narrows the cause
Leaks only in wind-driven rain may point to head or side flashing; winter moisture without rain may be condensation.
Water can travel around the curb
Underlayment and step flashing direct water even when the visible sealant looks intact. Opening roofing may be needed to inspect hidden layers.
Replacement timing matters
When the roof is being replaced, an old skylight may be more economical to replace before new roofing is cut around it.
Details worth checking
- Glazing and frame
- Curb height
- Head, side and sill flashing
- Underlayment tie-in
- Interior condensation
- Roofing above the opening
Continue with a related roofing topic
B.C. roofing advice
Roofing advice is most useful when it gives a direct answer, explains the conditions that change it and points to a practical next step.Skylight leak repair
Skylight leak repair follows the project decision, work sequence and closeout checks behind treating the skylight, curb and surrounding roof as one detail.Chimney flashing problems: repair or replacement?
Chimney flashing can be repaired when failure is isolated and the surrounding roofing and masonry are sound.Apply the information to the actual roof
Share the property, roof type, observed condition and decision timeline. A site-specific review can confirm which parts of the guidance fit and where the scope needs to change. The decision should also account for curb height.
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