Skylight leak questions: separate the unit, flashing and surrounding roof

Record the leak pattern from safe interior locations

Note when water or staining appears, the interior location, recent weather and whether the observation changes over time. Photograph the surrounding ceiling or finish without opening building materials or approaching an electrical hazard.

Do not conclude that the skylight unit is the source solely because staining appears nearby. Keep the observed location and the suspected cause in separate fields.

Ask the inspection to separate connected components

Department of Energy building-science guidance identifies the skylight unit, the connection between frame and sash, flashing, roof covering, underlayment, sheathing and framing as relevant areas in a water-infiltration assessment. Ask which of those areas were accessible and what evidence was found.

Request photos or notes that locate each finding. If the provider cannot inspect a concealed layer, the report should retain that limitation instead of presenting a complete diagnosis.

Make the proposed work name the problem it addresses

Ask whether the recommendation concerns the skylight unit, flashing, adjacent roofing, damaged supporting materials or more than one item. The proposal should identify removals, new materials, tie-ins and interior work that is included or excluded.

If testing is proposed, ask who performs it, how the building interior will be protected and what the test can and cannot establish. Do not perform roof-level water testing yourself or direct water in a way that could worsen damage.

Keep findings and completion evidence together

Save the inspection report, accepted scope, approved changes, product information, supplied photos and completion notes. Record whether interior finishes or concealed moisture need a separate qualified assessment.

After work, monitor the original observation area safely and document any recurrence. A dry period immediately after repair is not proof of long-term performance; use the written scope and later observations for follow-up.

Related guides

• What to ask for in a roof inspection report
• Roof leak checklist: what to record before the inspection
• Repair or replace your roof? Questions that clarify the choice