One of the top questions we get asked is … “What is a curb mount skylight?”

While the simple answer  ” A skylight designed to fit on a curb”  might work for some people, most people would like more details. 

To start off with a curb is a raised frame that provides a surface for mounting mechanical units such as skylights onto a roof.  The material used to build these curbs will vary depending on the application and the specifications for the project you are working on. Most building codes will require at least a 4″ high curb on a pitched roof and 9″ – 12″ high curb for a flat roof. Of course,  you should always check state and local building codes before starting this kind of project.

Flashed Curb

Most residential applications will consist of a wooden curb built using nominal cut lumber such as a 2×4, 2×6 or 2×8 laying on it’s edge. This wooden frame (curb) will be attached to the roof deck around the opening already cut in the roof. This wooden curb is going to provide an elevated mounting point for our skylight.  As you can see from the picture above, the prebuilt curb has been attached around the rough opening in the roof and the flashing and shingles have already been done. This curb is ready for the new skylight to be set in place.


This picture shows you exactly how the curb is mounted to the roof deck and how the skylight is mounted to the curb.  Of course each application will be slightly different and if you are not sure about what you have or what you need then please give us a call at 303-296-9696 or send us an email at