What Is A Pallet Racking Starter Bay And Add-On Bay?

A starter bay is just the general term for the first bay in a run of pallet racking.

It is made up of two frames, with beams in the middle. Each frame is two posts with the zigzag bracing in between, so you have one frame on either side, then your beams connect through the middle. Generally, it is two beams per level, because you need to hold the pallet up from front to back.

From there, the number of levels can change. It might be three levels, four levels, five levels, six levels or seven levels. That part really depends on what the customer wants to store, how high the warehouse is, how high the pallets are and what forklift they are using.

As a very broad generic term, a starter bay is usually two frames and a few beam levels in the middle. A lot of the time that works out to be the best fit, because the uprights might be around 4.8 to six metres high and the pallets might be around 1200 high, so physically that is what tends to work best.

A starter bay can also sit by itself in a warehouse, bolted down and loaded, no problem. But if you have more room left and right, that is where add-on bays come into it.

What Is An Add-On Bay?

An add-on bay is basically one more frame and additional sets of beams.

Because your starter bay already has two frames, the add-on bay only needs one extra frame to keep the run going. The beams then click onto the end and the racking extends further along.

The easiest way to think about it is like a piano accordion. You start with the first bay, then keep stretching it out with add-on bays for as far as the warehouse allows.

So just to keep it simple, a starter bay is two frames and beams in the middle, while an add-on bay is one frame and the same amount of beams within it.

How The System Works Together

You start with one starter bay, then work out how many add-on bays you need beside it. You might have one starter bay and three add-ons. You might have one starter bay and ten add-ons. It just depends on the warehouse, how much room you have and how many pallet positions you need.

If you have one run of racking, that run needs one starter bay. If you have two runs, you need two starter bays. If you have three runs, you need three starter bays, and so on.

Then each of those runs can have a different number of add-on bays depending on how the warehouse works out. One run might be longer, one might be shorter, and another might have to stop because of access, workflow or the shape of the building.

How Long Can A Pallet Racking Run Be?

Technically, there is no real limit to how long a run can be.

In reality, the warehouse is what decides that. The size of the building, the layout, the access, the forklift movement and the way the business operates will all determine where that run needs to stop. 

So while you can keep adding onto a run, at some point the warehouse itself becomes the limiting factor.

How Many Runs Can You Have In A Warehouse?

As many as the warehouse allows.

That might be one run, two runs, five runs or a lot more. It all comes back to the size of the warehouse and how the layout needs to work.

Each run starts with one starter bay, and then the rest of that run is made up of add-on bays. That is the basic principle repeated throughout the warehouse.

Does The Same Idea Apply To Other Racking Systems?

Roughly, yes.

At the end of the day, what we are trying to do is store as much as we can in the most practical way possible. So a lot of racking systems work off the same basic idea. You start with one set unit, then extrapolate it out across the warehouse.

That same principle applies across pallet racking, drive-in racking, double deep, cantilever, A-frame racking, push back, shuttle systems and even longspan shelving. The exact components change depending on the system, but the thinking is pretty much the same.

You start with the base unit, then repeat it throughout the warehouse to fill out the space as efficiently as possible.

About Leo Kanas

Leo Kanas brings over two decades of hands-on experience in warehouse storage systems and racking design. As Project Manager and lead designer at Macrack Australia, Leo works at the intersection of engineering, layout optimisation, and customer-driven solutions. He holds qualifications in project management and industrial design, and has overseen dozens of warehouse redesigns across Australia. Leo is passionate about helping businesses unlock hidden capacity, streamline workflows, and future-proof their storage systems.