How To Support Round Ducts On Roof

Consideration must be given with restraining ducts to avoid development of excessive internal duct stresses caused by expansion or contraction due to temperature variations.

How to support round ducts on roof.

Round duct size equipment rail length. Also offsets are elbows. Use an intermediate support on elbows where the center line length plus 4 0 is greater than the support spacing for the duct type. Use your leg a workbench or the ground to support the back side of the pipe.

Locate a support within 2 0 of the ends of any elbows including the elbows that may be turning vertically to penetrate the roof. A foot pad must be provided for each leg to prevent the support from cutting into the waterproofing membrane. 5 0 48 1 4 to 60 dia. Php d duct support the php d duct support leverages a goal post design with a single crossbar below the duct to support all sizes of square or round ducting cable trays and piping.

4 0 36 1 4 to 48 dia. These goalpost type duct supports used for ducting on a flat roof are fabricated from angle iron for small ducts and from channel iron for very large ducts. 3 0 24 1 4 to 36 dia. Assemble the metal ducting like a zipper.

This support can meet nearly all height requirements above the roof surface and is approved for seismic and high wind applications. Use one hand to keep the two edges close and the other to apply downward pressure. 2 0 12 1 4 to 24 dia. Sometimes concrete pads are placed under each foot.

Support systems for ductwork may provide restraint in three directions against displacement and rotation. When assembling pipe start at one end and work the seam together like a zipper. 7 0 72 1 4 to 84 dia.