Understanding pallet stacking and the clear height of a building

How high is the right height?

Palletized storage is a pretty customized world when it comes to load heights. There are almost as many load heights in use as there are operators. Luckily for us however, putting pallet loads onto racks requires some standardization in the module of the racking itself. It turns out that almost half the racks currently manufactured for high pile palletized storage use a bar to bar vertical dimension of 72”. They accommodate pallet load heights of up to 64”. The two second most configured racks have 64” and 80” bar modules corresponding to 56” and 72” pallet loads. We think that there are opportunities for maximizing the ‘cube’ of today’s large scale distribution facilities by moving up to 36’ clear over the currently popular 32’ clear.

Here is a diagram of pallet stack heights related to building clear heights. pallet stacking and clear height This diagram and the following table summarize the three most utilized pallet rack configurations, showing how high the top of the last pallet load is for each. The diagram is to scale and shows a ten foot distance between the stacks which as we will see later is a preferred aisle width for swing reach trucks lifting to these heights.

Pallet stacking heights table

Pallet Load Height 56″ 64″ 72″
Rack vertical module 64″ 72″ 80″
Number of pallets in rack Clear Height Clear Height Clear Height
4 20′-8″ 23′-4″ 26′-0″
5 26′-0″ 29′-4″ 32′-8″
6 31′-4″ 35′-4″ 39′-4″
7 36′-8″ 41′-4″ 46′-0″

The middle column represents around half of the rack configurations currently manufactured. In a 32’ clear building it shows you can stack 5 pallet loads high. If you are in a 36’ clear building you can get an extra load and stack 6 high for a 20% increase in pallet positions. The third column shows that with 72” pallet heights you can stack 4 high in a 32’ clear building. Stacking 5 high is just a bit above 32’, but you can argue that with normal roof slopes a significant portion of the building could be stacked 5 high. In fact a portion of that building could even be stacked 6 high. A 36’ clear building ensures that all of the building could be stacked at least 5 high totaling 25% more pallet positions. Back at the first column we see that with a 56” pallet load height you can stack 6 high in a 32’ clear building. Stacking 7 high puts us just above 36’, but as alluded to in column 3, you could likely stack a significant portion of a 36’ clear building 7 high and achieve 12% more pallet positions.

It appears that there is a clear opportunity for most users to increase the pallet capacity of a building footprint by 12% to 25% by going to a 36’ clear height over a 32’ clear height.

Analysis and report prepared by HPA Architecture, Inc. The complete report Supersized Buildings: New Trends in Clear Height is available here.