The one thing our customer service team gets asked the most is how to correctly measure a curb mount skylight. Especially if you are replacing a damaged skylight or updating a skylight. We hope this helps.
Residential curb mount skylights generally sit on a site-built curb that is made of 2×4 or 2×6 dimensional lumber sitting on its edge. The curb is then flashed to the roofing material to provide a water tight seal. Standard, uninsulated curbs are usually 1.5” thick, therefore the difference between inside curb measurement and outside curb measurement is generally between 3” – 3.25”.
When replacing a curb mount skylight, the best way is always to have the skylight removed and the bare curb exposed for a precise measurement. However, we understand it may not always be feasible. For preliminary measurements, there are a couple of ways you can measure the size of your curb without removing your skylight.
