Minimum Roof Curb Height

This dimension should be measured from the finished surface of the roof which would.

Minimum roof curb height.

Dimensions are in inches 5. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. Comply with local code requirements for minimum curb height but in no case shall curb height be less than 18 inches as measured from top of bar joist to top of curb nor shall curb height be less than 8 inches as measured from top of roof membrane to top of curb. The curb should provide a minimum clearance of 10 inches between the top of the finished roof surface and the top of the wood nailer continuous around the curb perimeter.

Curb height 4. In no case should the curb be less than 14 inches in height. Bs 6229 2003 flat roofs with continuously supported coverings code of practice and bs 8217 2005 reinforced bitumen membranes for roofing code of practice both state that if unwanted water ingress into the building is to be avoided all weatherproofing upstands occurring around the roof area. Head flange width should be increased to 12 or more for roof pitches less than 5 in 12 2.

Roof mounted mechanical units shall be mounted on curbs raised a minimum of 8 inches 203 mm above the roof surface or where roofing materials extend beneath the unit on raised equipment supports providing a minimum clearance height in accordance with table 1509 7. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. See figure 6 6. If the curb does not include a counterflashing receiver.

All roof curbs are a standard of 20 in height. Which would include abutments rooflights and service vents etc must have a minimum height of 150mm. For example if you have an upblast fan with a 19 x 19 fan base you would need to order a 17 5 x 17 5 roof curb.