Roof framing around openings is sized per architectural and mechanical plans. Steel beams frame the opening with angle framing consisting of L5x3x1/4 and L3x3x1/4 angles attached with 3/16-inch fillet welds. The vertical leg of the joist is trimmed where it intersects the steel beam. Contractors may use Option B for framing connections as desired. Roof decks are welded to the angle framing, and openings smaller than 12 inches in diameter require reference to detail D3/S521.
OPENING SEE ARCH/MECH OPTION B NOTES: 1. SEE DETAIL D3/S521 FOR OPENINGS LESS THAN 12" IN DIAMETER. 2. 3. SEE TYPICAL ROOF TOP MECHANICAL UNIT SUPPORT DETAIL(S) FOR FRAMES UNDER MECHANICAL UNITS. ROOF DECK TO BE WELDED TO ANGLE FRAMING. TRIM VERTICAL LEG AT JOIST STEEL BEAM, SEE PLANS L5x3x1/4 (LLV) x 0'-6" TYP. CONTRACTOR MAY USE OPTION B IF DESIRED ANGLE FRAME L5x3x1/4 (LLV) 3/16 TYP TYP 3/16 3/16 3/16 TYP 3/16 A A SECTION A-A OPEN OPEN OPEN TRIM VERTICAL LEG AT JOIST 3/16 TYP 3/16 STEEL BEAM, SEE PLANS 3/16 TYP 3/16 TYP 3/16 3/16 TYP 3/16 3/16 ANGLE FRAME L3x3x1/4, TYP L3x3x1/4 x 0'-6" TYP. CONTRACTOR MAY USE OPTION B IF DESIRED L3x3x1/4 x 0'-6" TYP. CONTRACTOR MAY USE OPTION B IF DESIRED OPTION B
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