Roof Curb
Installation
It is recommended that the curb be installed directly on the support members and fastened to the supports using tack welds or other equivalent methods. Properly supported decking should be installed inside the air handler section of the curb when this method is used. (See Figure 1)
Figure 1. Cross section of typical curb installation on new construction
Typical Curb Installation Checklist
•Verify that the roof structure can adequately support the combined weight of the unit and curb assembly.
•Ensure that the selected installation location provides sufficient service and operational clearances.
•Remove any twist within the curb due to roof supports and square the curb.
•Level the curb.
•Secure the curb to the roof support members.
•Install
•Install cant strips around the curb.
•Bring field supplied roofing felt up to the top of the curb nailing strips. ail felt into place.
•Install field supplied flashing under the lip of the curb flanges and over the felt.
•Apply sealant to the four corners. Caulk all joints between the curb and the roof. Attach the gasket material to the curb’s top flanges (entire perimeter) and to the supply and return air duct opening panel flanges.
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