Why You Should Use Pallet Rack Row Spacers

Managing a warehouse of any size requires the use of many different types of equipment and materials. Likely the most important items for selective pallet racking involve row spaces, which are steel brackets that are designed to connect a row of racking to a nearby row. These spacers can come in the form of steel rods, bars, or channels.

While not all pallet rack applications require row spacers, these items offer considerable safety and structural advantages. Along with providing extra stability, row spacers also offer fire protection that ensures all rack levels can be reached by your facility’s sprinkler system. This article offers a detailed guide on why your warehouse or facility should use pallet rack row spacers.

Last updated: July 2026. Reviewed by the Quality Material Handling Inc. Rack Safety & Maintenance team.

Quick answer

Pallet rack row spacers are steel brackets, rods, or channels that connect back-to-back rows of racking to maintain a consistent flue space between them, which is required by most fire codes so sprinkler water can reach all rack levels. The 12-inch spacer is the most common size, typically creating around 6 inches of clear flue space plus overhang, though the exact size needed depends on your local building code’s minimum flue space requirement and your specific racking configuration.

What are Pallet Rack Row Spacers?

Row spacers are designed to be positioned between uprights in order to create even and consistent spacing between multiple pallet rack rows. Along with providing your warehouse with a more uniform look, these spacers will also increase the stability of your pallet rack rows, which should keep your employees and personnel safe.

Why You Need Row Spacers

As mentioned previously, you don’t need to use row spacers for all pallet rack applications in your facility. For instance, row spacers are unnecessary for a single pallet rack row. Instead, you could use wall ties to add stability.

If you have relatively short racking systems that you keep bolted to the ground, row spacers may not be needed since it’s considerably less likely that the uprights will move. Even though there are several applications where row spacers aren’t required, many storage applications in warehouses would benefit significantly from having them installed.

1. Keep Longitudinal Flue Spaces Clear

If you own or manage a warehouse, you’ll likely want it to be compliant with state building codes. Maintaining compliance in your warehouse improves overall safety while also helping you avoid high fines when a safety violation is identified. Once you’ve installed row spacers in the correct positions, they will keep pallet rack rows apart from each other by a minimum distance, which allows these spacers to eliminate code issues with longitudinal flue spaces.

Keep in mind that the row spacers you use must be long enough. In the event that local building codes require longitudinal flue spaces of 6″, you’ll likely need more than a 6″ row spacer. There would be around 3″ of overhang on both sides of the pallet, which would cover the entire 6″ spacer. In this scenario, your flue space would be at 0″. You can mitigate this issue by choosing a 12″ spacer to place between pallet rack rows.

2. Effectively Double the Depth of the Uprights

Having the right height-to-depth ratio is essential with the pallet racks in your warehouse. According to the American National Standards Institute, normal anchoring should be used for racks that have a max height-to-depth ratio of 6/1. If the ratio is higher than this, the anchoring you use must resist 350 pounds of force at the uppermost level.

You could also use row spacers to connect multiple rows of racking that would normally have ratios of more than 6/1, which would reduce the height-to-depth ratio and provide stability to the entire system. The purpose of these guidelines is to make sure that your racking system is stable at all times.

3. Row Spacers Keep Pallet Rack Rows Aligned

In the event that you need to maintain a consistent space between rows of pallet racking in your warehouse, having row spacers installed is the simplest and most affordable way of achieving this goal. Make sure that at least one spacer is added to each upright column to keep both of the rows straight throughout the whole distance of your racking system.

4. Fire Protection and Rack Safety

Safety is the main reason why building codes are written in the first place. When it comes to warehousing facilities, fire safety is of utmost importance. If pallet racks are incorrectly positioned, the water from overhead sprinklers may be unable to reach the bottom rows.

Overhead sprinkler systems have been designed to push water to all inventory and rack levels. If you’re using a back-to-back configuration for your pallet racks, you’ll need to create flue spaces between the rear areas of both rack structures. The row spacers you use will serve as stability for the two systems since they are unable to be braced against one another. This placement also ensures that the flue space remains intact.

5. High-density Pallet Storage

Row spacers are commonly used for high-density storage systems to provide the frame line that accommodates the depth of deeper lane systems. Numerous columns, row spacers, and uprights produce an upright line in a drive-in/thru, pallet shuttle, pallet flow, or push-back system.

What is Flue Space?

Flue space is the term commonly used in warehouse settings to describe the space that exists between multiple pallets and between uprights and pallets. It can also describe the space in each row that is parallel to the direction from which the loading takes place. When you stand in an aisle, these spaces are the gaps that you see. When the term longitudinal flue space is used, it indicates the space between at least two rows of racks.

In the event that your warehouse space is currently limited, leaving space between your pallet rack rows only serves to waste space. Row spacers give you the opportunity to maintain flue spaces in a manner that your warehouse can benefit from. For instance, having the right amount of flue space allows you to avoid pallet and load damage by making sure that they can’t crash into another row’s bay.

Once you’ve installed pallet rack row spacers, you’ll also be able to avoid substantial fines in regards to fire safety. You can make a flue space to effectively bury building columns as well.

How Many Row Spacers Should You Use?

The number of row spacers you require depends on how tall your system is. During this process, make sure that the row spacers you choose will provide the right amount of stability to your racking system.

The sizes of row spacers that are most commonly used include 6″, 8″, 10″, and 12″ varieties. In some scenarios, you may need to use 18″ row spacers. The 12″ variety is the most commonly used length. As touched upon previously, a 12″ row spacer gives you around 6″ of total flue space between each row as well as 3″ of overhang.

What To Consider When Purchasing Row Spacers

There are several things you should consider when you’re getting ready to purchase row spacers. For instance, the row spacers you choose must be compatible with your pallet racking systems. It’s also essential that the spacers are correctly installed if you want them to work as intended.

1. Compatibility

While some row spacers are compatible with nearly every type of pallet racking, most options are only compatible with one or two pallet racking styles. For instance, certain row spacers are solely compatible with structural or roll-formed spacers. Another roll spacer might be compatible with slotted and teardrop pallet racking styles. Make sure that you know the exact types of pallet racking you have in your facility before making your final purchasing decision.

2. Row Spacers Per Upright

The height of the pallet racking determines how many spacers are required per frame. These guidelines are:

• Uprights between 4-14 feet tall require at least one row spacer
• Uprights between 15-24 feet tall require at least two row spacers
• Uprights between 25-34 feet tall require at least three row spacers

Row spacers are typically positioned along the upper horizontal brace of each upright. There shouldn’t be over 10 feet of space between row spacers.

3. Placement and Installation

After you’ve selected the number and type of row spacers you need, they must be properly installed for your racking system to gain the support it needs.

• Make sure that the spacer for the bottom row is installed 5″ or higher from the floor
• Install the spacer for the top row beside the highest horizontal strut
• Install any intermediate row spacers beside the strut connections while at the same time maintaining equal distances
• Avoid any interference with rack beams, struts, and other system components

Row spacers vs. bolting racks to the floor

A common question is whether row spacers are still needed if racking is already anchored to the slab. Floor anchoring primarily resists tipping and lateral movement at the base of each upright, but it doesn’t maintain the flue space between back-to-back rows the way a row spacer does. In most double-row or back-to-back configurations, both anchoring and row spacers serve different purposes and are typically used together, since anchoring addresses stability while row spacers address code-required spacing and alignment.

Confirming your local flue space requirement

Minimum flue space requirements are typically set by NFPA 13 and referenced in local fire and building codes, but the exact number can vary based on your storage height, commodity classification, and whether your facility has in-rack sprinklers. Rather than assuming a standard 6-inch flue space applies to your facility, it’s worth confirming the requirement with your local fire authority or a fire protection engineer, since undersized flue spacing is a common finding during fire inspections.

Our experience: With over 32 years of experience in material handling, QMH specifies and installs row spacers as part of new and retrofit racking projects, working to confirm the correct flue space for each facility’s fire code and storage configuration rather than defaulting to a standard size.

Why Choose QMH?

At QMH, we have more than 30 years of experience in meeting all of the warehousing, distribution, and logistic needs our clients have. We offer end-to-end solutions that cover everything from management of permit approvals to full-service execution. From pallet rack mezzanines to high-density pallet racking, we’ll help you discover the solutions that are right for your warehouse. Call us today if you have any questions about row spacers and how they should be installed in your facility.