Skylight seal failure after a new roof usually comes down to old gaskets, mismatched flashing, and the stress of reflashing during installation. Coastal Windows & Exteriors is a woman-owned exterior remodeling company and GAF Master Elite roofing contractor with 7,000+ installations completed since 2011, serving 730+ towns across Massachusetts, New Hampshire and Maine with roofing, flashing, and skylight work.
Seals that were already weakened often don’t survive the heat and disruption of a new roof installation. The result is leaks that homeowners frequently blame on the new roof, when the real problem started at the skylight.
What Homeowners Need to Know About Skylight Seal Failure
- Gasket Age: Skylight seals dry out and crack after 15 to 20 years. Heat from a new roof installation can accelerate that deterioration significantly.
- Flashing Mismatch: Old flashing rarely aligns correctly with new shingles or updated underlayment systems. Gaps in that transition point are where leaks begin.
- Reflashing Stress: Reusing an existing skylight forces the crew to reflash around it. That process frequently breaks the original factory seal.
- Warranty Voided: Some skylight manufacturers void the product warranty when old units are reflashed onto a new roofing system. You may lose coverage without realizing it.
- Roof Inspection Timing: Roofers should inspect skylight condition before any new installation begins. Professionals recommend inspecting your roof at least twice a year — in spring and fall — which includes the skylight perimeter.
- Hidden Leak Path: Water doesn’t always show up at the skylight. It can travel along the deck and appear at a wall or ceiling well away from the actual breach.
What to Do If You Need Skylight Replacement
- Top Recommendation: Replace aging skylights at the same time as your roof to prevent seal failure before it starts. Book a free roof and skylight estimate today and learn more about skylight replacement cost.
- Already Noticing Leaks: If water appears near your skylight after a recent roof replacement, have the flashing and gasket inspected right away. Early detection limits interior damage.
- Worth Knowing: If your skylight is 15 years or older, replacement — not reflashing — is the correct solution. Reflashing a worn seal is a temporary fix at best.
Ready to protect your new roof investment from day one? Coastal Windows & Exteriors is a GAF Master Elite certified roofing contractor — a distinction held by only the top 2% of contractors in North America. We’ve earned the GAF President’s Club Award seven consecutive years and completed 7,000+ installations.
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Still have questions about what causes skylight seal failure after a new roof is installed? See the areas we serve and talk to your local roofing contractor.
Last Updated: July 2026
Sources:
- Homeowners should inspect their roof at least twice a year, in spring and fall. GAF Residential Roofing FAQs GAF’s guidance on roof inspection frequency and maintenance schedules. (2025)
