A structural box, usually made of galvanized steel, that acts as the mounting base for rooftop units, exhaust fans, and skylights. The curb is flashed into the roofing membrane to prevent water leaks. It supports the weight of the equipment, creates a level mounting surface on pitched roofs, and houses the duct drops that penetrate the roof deck into the building below.
Heard on the job
The crane is arriving at ten, so make sure the roof curb is perfectly level and the gasket is laid down.
Insider tip
Always check the curb for squareness by measuring corner to corner before the crane drops a five-ton unit onto it.
Also heard as
- curb