Key Facts When Choosing a Sprinkler System for Pallet Racks

Choosing the right sprinkler system is crucial for any building, especially one that stores products in mass. According to the National Fire Protection Association, an average of 1,210 warehouse fires occur annually. While these fires make up a mere 1% of all structure fires, they rack up an impressive $155 million in damages.

A sprinkler system offers a quick?and, more importantly, automatic?fire deterrent to reduce the chances your building will be a complete loss. Unfortunately, not all warehouses are best suited to the same system type. It's essential to understand the key facts when choosing a sprinkler system for pallet racks.

Factors to Consider When Choosing a Sprinkler System

Storage warehouses come in a variety of shapes and sizes. From food to cleaning chemicals and beyond, every product sold has a storage facility somewhere. The sprinkler system chosen should be based on what needs to be stored, as well as the pallet types themselves.

The sprinkler system will also control what you can store in the space (for example, sub-freezing items won't work well with wet pipes), how high you can store inventory, and the required aisle widths. Those last two factors are particularly important to the pallet size you need to store. Given this, it's best to choose a sprinkler system and pallet rack system at the same time to ensure compatibility.


The National Fire Protection Agency (NFPA) 13 is a set of codes that regulates the suitability of warehouse sprinkler systems. It covers everything from materials to installation plans and beyond. The NFPA 13 has remained largely unchanged in the last thirty years, though, small changes were made in 2016.

If your warehouse is equipped with a non-compliant system, you could be fined, but that's really a small concern when compared to the decreased fire protection a poorly planned system offers you and your staff.

Types of Sprinklers

Wet Pipe -- Wet pipes are the most common sprinklers utilized today. Water continually sits in the pipes and is immediately dispersed once the system is triggered. This system tends to be the least expensive to implement. However, they won't work in warehouses with temperatures below freezing.

Dry Pipes -- Commonly used in temperatures below freezing, in a dry pipe system, air or nitrogen is discharged to activate the water into the pipes -- otherwise, it might freeze before it can deploy. Dry pipe systems do have a high installation cost.

Pre-action -- Pre-action systems are useful for environments that are at risk for water damage. Air is maintained in the system, and the pipes remain pressurized. The system is controlled electrically once a trigger point is met. They are best in warehouses with above freezing temperatures but can be installed in colder environments with modifications.

Deluge -- Deluge systems are used when a significant amount of water is needed to deploy rapidly. A heat detection system triggers electrically controlled valves and releases water. Water is not always in the pipes, making them a good option for areas with temperatures below freezing.

Foam-Water -- Commonly used for items stored that are "high-hazard," including flammable liquids, foam-water is excellent at putting out the flames, suppressing toxic smoke and vapors, and stopping any chance of rekindling. These require smaller pipes and less water.

Types of Storage Pallets

Storage pallet options vary widely. When making a selection, a variety of factors, such as floor space, loading, and unloading order, need to be taken into consideration.

Block Stacking -- With block-stacking, loads are stacked on top of in each other and stored in "blocks," sometimes referred to as lanes. Each lane is stacked up to a specific height and weight determined by the product. Pallets are used from the closest block to the front. This storage method is cost-effective and can be operated anywhere with open space.

Stacking Frames -- These are pallet frames that can be built and moved around as needed. Due to the stacking nature, vertical storage is possible.  

Single-Deep Pallet Rack -- Single-deep pallet racks allow access to every pallet stored on the shelf and avoid the issue known as "honeycombing" where holes can form once pallets are removed. This is the standard storage method in many warehouses, but it requires significant storage space -- typically separate from a storefront.

Double-Deep Rack -- Similar to the single-deep, this places two racks together before storing on a pallet. With this type, fewer aisles are needed. It is not as efficient as a single-deep, though, as it can create the honeycombing effect.

Drive-In rack -- Drive-in rack systems utilize five to ten load spaces with drive-in lanes to remove and load pallets. They require a forklift and, therefore, wider aisles than other storage pallet options. Last in, first out applies to this pallet type.

Pallet Flow Rack -- Loads are removed and move down a conveyor belt in a first-in, first-out stock rotation. When one is moved, the next slides forward. Pallet flow racks are great for warehouses with high throughput, but they are costly.

Push Back Rack -- Similar to other last in, first out options, a new load is added and pushes older loads backward.

How to Pick

As you can tell, there's a lot more to setting up a fire-safe warehouse than selecting a single sprinkler system. Start with the product. If you store perishable or frozen goods, that checks a wet pipe system off the list.

Next, you have to dictate how the product is stored and transferred out. Following perishable or frozen goods, it's a good bet to assume first in, first out, to avoid spoilage.

This requirement would rule out a handful of pallet types and leaves you with the common push back rack, drive-in rack, and others such as single-deep and double-deep that give you access to everything at any time in terms of taking it out. All that's left to do from there is consider floor space and ceiling height.

It's worth mentioning that the closer boxes are to a sprinkler system, the more likely a sprinkler system will struggle to work. After all, it can't do its job if boxes block the water from spreading. Don't forget, always keep NFPA 13 compliance in mind before making any final decisions on the sprinkler system in your storage warehouse.