Round core-drilled penetrations up to six inches in diameter through concrete on steel deck assemblies without additional slab reinforcement require twelve-inch minimum center-to-center spacing when positioned through the top of the deck flute, and eighteen-inch minimum center-to-center spacing when positioned through the deck web or bottom flute. No single penetration shall cut through more than one deck web. Furthermore, the sum of penetration widths within a ten-foot width perpendicular to the deck span shall not exceed twenty-four inches. When core holes are drilled after concrete placement, existing reinforcing bars must remain uncut. Steel decking beneath unsupported holes or block-outs must stay in place until the concrete achieves its full design strength.
NOTES: 1. THIS DETAIL APPLIES TO ROUND HOLES ≤6"Ø CUT IN CONCRETE ON STEEL DECK WITHOUT ADDITIONAL SLAB REINFORCEMENT. 2. NO PENETRATION SHALL CUT THROUGH MORE THAN ONE DECK WEB. 3. WHERE PENETRATIONS ARE CUT AFTER CONCRETE IS PLACED, NO REBAR SHALL BE CUT. 4. STEEL DECK UNDER UNSUPPORTED HOLES AND/OR BLOCK-OUTS SHALL REMAIN IN PLACE UNTIL AFTER CONCRETE HAS REACHED DESIGN STRENGTH. HOLE CL CL 12" MIN TOP OF DECK FLUTE BOT OF DECK FLUTE DECK WEB CL CL TO ADJACENT HOLE CL 18" MIN D 1 D 2 D + 10' WIDTH PERPENDICULAR TO DIRECTION OF DECK SPAN D 3 D 4 D 5 D 6 1 D + 2 D + 3 D + 4 D + 5 D ≤24" 6 PENETRATION THROUGH TOP OF DECK FLUTE PENETRATION THROUGH DECK WEB AND/OR BOTTOM OF DECK FLUTE 24" MAXIMUM TOTAL WIDTH OF PENETRATIONS IN 10' WIDTH
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