Roofing curb provides the roof surface to install mechanical or HVAC equipment, as well as roof accessories such as air conditioning, fans, skylights, cooling units, pipes, and stacks. To provide protection against weather, the mechanical roof curb is equipped with integral flanges.
Special features include thermal isolation, vibration isolation, voice attenuation, pitch or adjustable slope, and heavy gauge construction.
There are many types of curbs. Options include metal roof curbs, flat curbs, pipes curbs, pitch curbs, and Skylight curbs. Curb adapters and expansion joint roof curbs are also available. A metal roof curb can be installed below or on the building roof panel. Components include waterwork, polystyrene gaskets, fiberglass insulation, and optional reducer shelves.
Often, the roof curb framing is made of sections of cold-formed steel. Flashing cells or caps are sometimes used. Metal equipment rails are commonly available. These roof curb accessories feature welded seams and a support shell made of galvanized steel. Rooftop adapters or curb adapters are also made of galvanized steel, typically from 14- to 18-gauge.
Models that are equipped with fiberglass insulation provide some sound attenuation. Typically, flat roof curbs are made of aluminum or stainless steel. They are available in a variety of heights and may feature a self-flashing base.