FAQ

1. What do I need to know about my roof before ordering a skylight?
o Roof pitch - to determine proper skylight, as deck mount requires 14 - 85
degree pitch
o Roofing material - for appropriate flashing, EDL - shingles, EDW - tile, EDM -
metal
o Rafter spacing - 16” on center, or 24” on center (for example) to determine
proper skylight width
2. How do I determine which deck mount skylight size I should order?
o Rough opening dimensions (the size of the hole needed in your roof) is the
correct way to determine the deck mount skylight size you need. It’s very
important to confirm your rough opening dimensions before ordering.
3. Do I need to purchase flashing separately?
o Yes, VELUX deck mount flashing is required for the “No Leak” installation
warranty and it’s sold separately because the type of flashing you need
depends on your roof type. Please refer to bullet #1 to determine which
flashing model you need.
4. Can a deck mount skylight be installed on a flat roof?
o No, VELUX deck mount skylights require a roof pitch between 14 - 85
degrees, but VELUX curb mount skylights can be installed on a flat roof.
5. What is the biggest difference between new skylight installation and
replacement of an existing skylight?
o New installation allows you to be precise with rough opening and placement
of the new skylight. When replacing a skylight, the exterior width of your
existing skylight and interior rough opening must be taken into
consideration. Additional work can be involved with the removal of an existing
skylight since a deck mount skylight needs to mount directly to the roof deck.