Inspection Installation Velux

Skylight flashing is critical — skylights are a common roof leak source. Must use manufacturer-specific flashing kit or proper step/counter flashing.

1. Check flashing kit — should be manufacturer-specific for the skylight model

2. Verify step flashing on sides is woven with shingles (not just surface-applied)

3. Check head (top) flashing extends under shingles above

4. Check sill (bottom) flashing directs water over shingles below

5. Verify no exposed sealant or caulk as primary weather seal (should be mechanical flashing)

6. Check from inside attic — any daylight visible around the frame? (leak path)

7. After rain: check for water stains around the skylight from inside

- Generic flashing instead of manufacturer kit (poor fit, guaranteed leaks)

- Step flashing not woven with shingles (water runs behind)

- Head flashing not extending under upper shingles

- Sealant used as primary waterproofing (fails within 3-5 years)

- Improper sill flashing (water backs up under skylight)

- Visible water stains around skylight on ceiling

Skylight shaft must be insulated and have a vapor barrier. Condensation on glass is normal in cold weather but excessive indicates problems.

1. Check skylight shaft walls — should be insulated (R-19 minimum) and have a vapor barrier

2. Verify shaft drywall is properly finished (no gaps or holes)

3. Check for condensation on glass — some is normal in cold weather, excessive indicates humidity problem

4. Verify operable skylights open and close properly

5. Check for blinds or shade operation if installed

6. Verify skylight glass is intact (no cracks, delamination, or haze between panes)

7. Check for drip marks indicating condensation running down walls

- Uninsulated shaft (condensation, energy loss)

- Excessive condensation (indicates indoor humidity too high or poor insulation)

- Shaft not sealed from attic space (air leaks)

- Operable skylight won't close properly (rain entry)

- Failed glazing seal (haze between panes)

- Drip marks on shaft walls from condensation