Skylights are one of the most common leak sources we find on San Francisco roofs, especially on flat roofs where water moves slowly past the curb. A reroof is the cheapest moment to deal with them, because the roofing around the skylight comes off anyway.
Replace or reflash?
| Condition | Usual recommendation |
|---|---|
| Skylight has leaked at the curb, but the glazing is sound and sealed | Reflash it with a new flashing kit during the reroof |
| Fogged, cracked or crazed glazing, or an old plastic dome | Replace the unit |
| Rotted or undersized curb on a flat roof | Rebuild the curb and replace or reflash the unit |
| Unit is fairly new and the flashing is in good condition | Leave it and integrate it into the new underlayment and membrane |
What does the code say?
Under California Residential Code R908.5, existing flashings, edgings, outlets, vents and similar parts of the roof assembly must be replaced where they are rusted, damaged or deteriorated. R908.6 requires flashings to be reconstructed according to the manufacturer’s installation instructions. Reusing a tired skylight flashing under a new roof is exactly what these rules are meant to prevent.
In San Francisco, the reroofing permit application asks which other items are being replaced, including skylights, so they go on the same permit as the roof.
Why not wait?
- Replacing a skylight later means cutting into new roofing and new underlayment around it.
- A leak at an old skylight can stain the ceiling and wet the deck under a roof that is otherwise brand new.
- One crew, one permit and one weather window cost less than two separate jobs.
We check every skylight during the inspection and list reflash or replacement as separate lines on the estimate, so you can decide. See skylight repair and replacement and roof replacement.
Request a free inspection and written estimate or call (415) 410-7917.
Sources: 2025 California Residential Code R908, reroofing (GoCodebook); SF.gov: apply for a reroofing permit.
Related services and local pages
Sources
- 2025 California Residential Code R908, reroofing (code text on GoCodebook)
- SF.gov: apply for a reroofing permit
Rules and maps change; confirm requirements for your address with your city or county building department.
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