Pallet Rack Spacing Guide

Improper pallet rack spacing can disrupt forklift operations, cause problems with inventory storage and retrieval, and compromise the safety of the entire warehouse. That’s why, you must carefully plan the various spacing measurements in your warehouse.

In this article, we’ll discuss in detail the various aspects of pallet rack spacing- from standards to the various types of spacing that must be considered when installing a pallet racking system. So, get started right away!

Pallet Rack Spacing Standards & Requirements

Governing bodies like OSHA (Occupational Safety and Health Administration), ANSI (American National Standards Institute), RMI (Rack Manufacturers Institute), and others have a certain set of safety standards and regulations that must be followed when installing a pallet racking system.

Some of these standards also provide standard pallet rack spacing measurements to ensure the safety of the warehouse employees.

• OSHA (Occupational Safety and Health Administration): The OSHA standards emphasize workplace safety more than anything else. According to section 1910.176(b), the aisles and passageways of every warehouse must be wide enough to handle forklift traffic. So, when planning the aisle width, always consider the pallet rack spacing for the forklift and other handling equipment that you will use.

• NFPA Fire Safety Regulations: The National Fire Protection Association has strict pallet racking spacing regulations. Every pallet racking system must leave a minimum of 18-inch vertical clearance and 36-inch aisle width for the fire sprinkler system to perform efficiently.

• Local Building Code Requirements: To adhere to your local fire safety requirements, you must research the local building code and follow the vertical and horizontal pallet racking spacing guidelines. In most regions, the minimum aisle width is set between 36 to 48 inches.

It’s best to do your research before deciding on the pallet rack spacing measurements. This will help you ensure that your pallet racking system follows local laws and industry standards. 

Categories of Pallet Rack Spacing

When it comes to pallet rack spacing, there are multiple areas to take care of. In this section, we’ll take a closer look at FOUR areas that you must plan for carefully.

1. Flue Spacing

Flue spacing, also called row or rack spacing, is the horizontal space between the pallets stored and the vertical clear space between back-to-back rows/racks. Flue space is critical to ensure airflow between racks and it improves the fire safety of your pallet racking system. 

There are two different types of flue space that you need to leave between racks:

• Transverse Flue Space: Minimum of 6 inches.
• Longitudinal Flue Space: Minimum of 3 inches. 

The NFPA (National Fire Protection Association) has set these standard measurements to ensure the water from the sprinkler system easily spreads through these flue spaces. 

2. Aisle Spacing

Aisle spacing means the width of an aisle between the pallet racking system. When deciding on pallet racking aisle width, you must consider the size of the forklift that you’ll be using in your warehouse. You must leave enough room for safe forklift maneuverability. Here’s a look at the standard pallet rack aisle spacing, depending on the forklift size:

• Standard Forklift: Full-size forklifts require 10-12 feet wide aisles. 

• Narrow Aisle Forklifts: Narrow forklifts can easily operate in an 8-10 feet aisle.

• Very Narrow Aisle (VNA) Forklifts: If you install a Very Narrow Aisle pallet racking system, 5-7 feet aisle width is enough.

3. Vertical Clearance

Within the shelves (beam levels), you must leave enough vertical space to store and retrieve pallets without collisions. The standard vertical clearance is 6 inches from the top of the inventory-loaded pallet. 

Similarly, you also have to leave a vertical clearing between the top of your pallet racking system and the ceiling of your warehouse. This vertical pallet rack spacing is necessary to leave space for the fire suppression system.

4. Wall Clearance

Much like pallet rack aisle spacing, it is important to leave enough room between the walls of your warehouse and your pallet racking system. This space makes sure that the inventory handling equipment doesn’t damage the walls during inventory storage/retrieval. 

Similar to the vertical clearance, a minimum of 6-inch clearance is suggested from the walls by both the OSHA and the NFPA standards. However, local regulations in some regions only require a 3-inch wall clearance. You should research your local laws before deciding on the wall spacing measurement.

Factors Affecting Pallet Rack Spacing

1. Forklifts & Other Inventory Handling Equipment

The type and size of forklifts and other inventory handling equipment directly impact pallet racking spacing measurements like aisle width and wall clearance. 

Each forklift model has a unique turning radius and maneuvering requirement. For example, standard forklifts need at least 12 feet of aisle space to operate efficiently. On the other hand, narrow aisle forklifts can work within aisles as narrow as 6 to 8 feet.

So, before deciding on the aisle width and wall clearance, accurately measure your forklift radius and leave space for easy maneuverability.

2. Type of Inventory

The size and weight of your inventory will also affect your pallet rack spacing measurements. 

For example, if you store lightweight inventory, you might not need the standard vertical clearance because of easy storage/retrieval. As for heavy-duty inventory, you should leave an extra inch or two of vertical clearing as well as transverse flue space to get extra room for safe storage and efficient retrieval. 

3. Seismic Activity

Seismic activity can cause racks to collide and collapse if they aren’t properly spaced. So, in areas where high seismic activity is expected, measurements like flue spacing should be adjusted accordingly. The extra clearance/space within racks and pallets could be the difference between safety and complete collapse. 

Conclusion

Proper pallet rack spacing is an important aspect of warehouse design. It ensures the safety of everyone in the warehouse and increases the operational efficiency of the pallet racking system. 

We hope our guide helps you understand the concept of pallet rack spacing. Use this information to create a safe and efficient pallet racking system that maximizes the storage capacity of your warehouse but also provides a safe workplace for everyone.