We had just installed new shelves and our experience is similar if not the same as John Guthrie's. We are in a basement with poured concrete slab floors, so weight load isn't a concern. Our units (tiers) are 10' tall, 42" x 30", bolted together with plates bolted to the bottom of the legs and at least 2.75" bolts into the floor through the plates. Ceilings are 16' tall with light fixtures at 11'. We do not use the top shelf for storing records, rather it acts as a dust cap. Rows are bolted back-to-back with 40" aisles between sections. Shelves are 18 gauge steel with 14 gauge "T" posts between tiers and at end posts. Two cross braces between each tier and at the back of each tier at approximately 2' and 10'. Units are not anchored to walls or between rows to maintain some flexibility in the event on a seismic event and minimize if not eliminate the domino effect. Shelves are clipped to uprights ("T" posts), not bolted.
Additionally, but not seismically related, bottom shelves are 6" off the floor to give some protection in case of flood like was experienced in '96 when the elevator sump pump could not handle one our infamous Pacific Northwest downpours. I've also installed three battery operated moisture detectors that are unfortunately not connected to the campus public safety alarm system - yet.
Hope this is helpful.
Jim Mullen, Records Manager
Oregon University System
P.O. Box 488
Corvallis, OR 97331-0488
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