A skylight curb is a raised frame, typically 2"x6" or bigger (code is 4" or taller), that is installed on a roof to provide a secure mounting base for a skylight. It elevates the skylight above the roof surface to ensure proper water drainage and waterproofing while creating a stable attachment point.

Why Curb Height Matters

A curb that is too short can lead to water pooling, leaks, and long-term roof damage. The 4-inch minimum required by most building codes ensures that water and debris shed away from the skylight frame properly, especially in heavy rain or snow.

How To Measure Your Curb

Before purchasing a curb mount skylight, measure the inside dimensions of your existing curb. Velux curb mount skylights are sized to fit standard curb openings. See our Velux Measurement Guide for step-by-step instructions.