Curb Outside Dimension (COD)
The Curb Outside Dimension (COD) is a critical piece of information for the ordering process. This will be the dimension of the unit that will be the base for the skylight or smoke vent. Compare this to a shoe box and the lid for the shoe box. The COD would be the dimension of the shoe box that must fit inside the net frame inside dimension (NFID) of the skylight or lid of the shoe box. The COD is typically one inch (1”) smaller than the NFID. The COD should include any flashing materials and would be the finished and flashed dimensions of the curb. The typical curb wall is 1.5” thick, unless otherwise specified. This dimension is critical for every installation and therefor the critical emphasis throughout the ordering process. We look forward to serving your daylighting needs.
Net Frame Inside Dimensions (NFID)
The Net Frame Inside Dimension or (NFID), is the measurement of the skylight or smoke vent frame. This will be the dimension of the unit that will fit over the roof curb. Compare this to a shoe box and the lid for the shoe box. The NFID would be the dimension of the lid that must fit over the shoe box. The NFID is typically one inch (1”) larger than the curb outside dimension. This dimension is critical for every installation and therefor the critical emphasis throughout the ordering process. We look forward to serving your daylighting needs.
Curb (Roof Curbs)
A raised frame on a roof that supports skylights, smoke vents, or hatches, providing structural support and proper drainage.
Daylighting
The use of natural sunlight to illuminate building interiors, reducing the need for artificial lighting and improving energy efficiency.
U-Value
A measure of how well a product (like a skylight) insulates. Lower U-values indicate better thermal performance.
SHGC (Solar Heat Gain Coefficient)
Indicates how much solar radiation passes through a skylight or window. Lower values help reduce cooling loads.
Fusible Link
A temperature-sensitive device used in smoke vents that triggers automatic opening in the event of a fire.
Drop-Out / Melt-Out Unit
A type of smoke vent or skylight that is designed to melt or drop out in high temperatures, allowing smoke to escape.
Fall Arrest System (PFAS)
A personal safety system used to prevent falls when working at height, often included with ladder installations.
Prismatic Dome
A skylight dome made with prismatic optics that help diffuse light evenly and reduce glare.
Toplighting
The strategy of bringing natural light into a space from above, typically through skylights or roof monitors.