Skylight Terminology & Definitions

Skylight Terminology and Parts

The first step to knowing your way around your skylight is to understand some basic skylight terminology.

See Roofing Definitions & Terms for more  information.

Plastic glazing, most commonly available in clear, bronze, or white but also available in other colors. Usually blown into a dome shape for aluminum framed skylights.
Annealed Glass
Glass that unsuitable for skylights. When it breaks it forms knife like edges that can cause extreme damage.
Material that holds the skylight up above the roof deck. Flashing water-proofs between the curb and the roofing.
Material used to waterproof any penetrations through the roofing, or used when a vertical wall butts up against the roofing.
Any type of transparent material that lets in light to the home.
Ice and Water Seal
Material used around the curb of the skylight to help with ice damming and condensation of the metal flashing.
Laminate glass
Safety glass used on the inboard sheet only. Used when the skylight is above 12 feet off the floor, or when the homeowner wants more protection from the sun’s rays that cause fading. Similar to the windshield glass on your car. It has a laminate layer over the glass, so when it breaks it will not fall into the home.
Roof Window
A skylight within arms reach. Designed to walk up to and open like a window but installed on the roof, usually in an attic.
Overhead glazing
See glazing… Another term for a skylight, usually used in commercial or large application settings.
Plastic type glazing that withstands impacts better than acrylics. Usually used in double or triple walled products such as Lexan Thermoclear or Polygal.
Material applied with a caulking gun to seal air and/or water out. There are only certain grades that can be used on glazing.
Opening in the roof that lets light into the interior spaces of the home.
Flashing pieces that are inter-laced with each roof course to allow water out at each course, compared to continuous flashing which doesn’t let water out until the end of the flashing or skylight.
Tempered Glass
Safety glass required by codes to be used on overhead glazing. Similar to the side windows of your car.

1 thought on “Skylight Terminology & Definitions”

  1. Thanks for helping me learn more about skylights. I actually didn’t know that there is a material used to waterproof penetrations through the roofing. I’m kind of interested to know if the design of this could differ depending on where the skylight is.


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.