Baseplate… Size Matters


Why upgrade from the Standard Baseplate?

Seismic baseplates are larger, thicker and have additional anchoring holes for options when rebar impedes the installation of anchor bolts.

Most rack companies offer a very small and thin baseplate (1/8” x 3” x 5”) as their standard baseplate with standard pallet racking components. This is what you may get for your frame if you are in a low seismic risk area where a larger baseplate is not needed for seismic resistance and there is no request made for a more substantial baseplate. The purpose of this blog post is to outline the importance of the baseplate and to help the rack user understand that it may be a wise decision to consider an upgrade from the standard simple baseplate, even in low seismic applications.

The baseplate is important because:

  • It distributes the column load to the floor slab. The larger and thicker the baseplate is, the less stress (PSI) is exerted on the slab.
  • It provides rotational restraint at the base of the column. Added rotational restraint at the base can significantly increase the actual capacity of the frame from the “pinned base” condition.
  • It transfers any uplift force that may exist (from seismic or other overturning effects) to the anchor bolts.
  • In the event of a fork-lift impact, it transfers the load from the column to the anchors and works to keep the column in its position, rather than being displaced. A second anchor in the aisle side column can also be beneficial to prevent the column from “spinning” if impacted.
  • It helps to prevent a collapse from progressing to the whole row if there is an incident where a fork-truck takes out a column.

An upgraded baseplate will result in improvement in all items, one through five above. The main argument against a heavier baseplate is cost, but when the total frame weight and cost are considered, the percent change by a baseplate upgrade is really surprisingly minimal. A standard 1/8” x 3” x 5” baseplate may weigh 0.6# as compared to a 3/8” x 5” x 7” baseplate weight of 3.7#, so upgrading to the 3/8” baseplate only adds 6.2# to the frame weight. If the frame weighs 200#, the difference is about 3% of the frame weight and an even lower percentage of the total project cost. Many rack users later regret not selecting this small upgrade to their rack purchase.