TinnerFlow™3rd YearSeismic / Cable RestraintsYELLOW · Check First
Seismic cables should restrain movement without pulling the duct out of line. Remove sloppy slack and adjust them per the approved seismic detail.
A loose seismic cable lets the duct swing before the cable catches it. That momentum can shock-load anchors, rods, and other trades.
Check the approved seismic layout, cable direction, anchor points, and whether tightening the cable pulls the main hangers out of plumb. Adjust to the required condition and document for inspection.
Do not leave seismic cable loops hanging loose because they “look safer.”
Loose seismic restraints can fail inspection and let ductwork swing hard during movement.
Final direction still comes from approved drawings, specs, manufacturer instructions, employer policy, foreman/detailer direction, structural/seismic details, and AHJ/code requirements.