Framing for a roof opening and mechanical unit curb spans between structural steel beams using an angle frame made of L6x4x5/16 angles running beneath the mechanical unit curb, with lighter L5x3x1/4 angles permitted if the unit weighs less than six hundred pounds. A secondary framing ring of L3x3x1/4 angles surrounds the duct opening. The steel deck flutes beneath the curb are solidly blocked using either a 1.5x1.5x1/4 hollow structural section six inches long tack welded to the steel deck or solid blocking connected to the deck. The steel deck is secured to the angle frame with three-sixteenths inch welds typically at the flats, and the vertical leg of the framing is trimmed at the support with sheet metal screws.
JK2RTS08 SOLID BLOCK THE FLUTES OF THE STEEL DECK BENEATH THE CURB OF THE MECHANICAL UNIT. THIS MAY BE DONE WITH A HSS1.1/2x1.1/2x1/4 x6" LONG TACK WELDED TO THE STEEL DECK OR WITH SOLID BLOCKING CONNECTED TO THE STEEL DECK. WHERE THE MECHANICAL UNIT WEIGHS LESS THAN 600#, THE L6x4x5/16 SUPPORT ANGLES MAY CHANGED TO L5x3x1/4 (LLV). ANGLE FRAME L6x4x5/16 (LLV) UNDER MECHANICAL UNIT CURB L3x3x1/4 AROUND DUCT OPENING TYP. STEEL BEAM NOTE: WELD STEEL DECK TO ANGLE FRAME. 3/16 TYP AT FLATS 3/16 TYP SEE ARCH/MECH CURB DIMENSION SEE ARCH/MECH OPENING FOR DUCT TRIM VERT LEG AT SUPPORT TYP SHEET METAL SCREWS
Members view this detail in full resolution, download the CAD files (SVG, PDF), and can adapt it in the built-in CAD editor — export DXF, DWG, or PDF.
Start membership