Understanding NFPA 13 Chapter 20: General Requirements for Storage in Industrial Properties

Most business owners don’t think about the fire sprinkler system in place unless required to do so. On a recent visit to the Riverside Planning/Building & Safety Division, my colleague Raymond and I had a conversation with a fire prevention specialist regarding the lack of awareness on the importance of fire sprinkler densities. As real estate agents, we spend a lot of time on lead generation and marketing, but it’s also crucial to study the real estate itself and its components — in this case, the fire sprinkler system. This particular issue could even be a deal breaker, as some businesses require specific fire sprinkler setups to comply with fire codes.

I began looking into fire sprinkler systems while researching high pile storage (12 feet or higher) requirements for e-commerce businesses, but realized that the importance of fire sprinkler densities extends far beyond just e-commerce.

The National Fire Protection Association (NFPA) 13 is a key standard for ensuring proper fire protection, especially in storage environments. Chapter 20 focuses on the general requirements for storage protection. In the following summary, I’ll provide industrial property owners with an overview of the key points, common concerns, and guidelines on how to effectively protect stored commodities.

Key Points for Storage Protection

1. Commodity Classification:

• Identifying the type of commodity stored is crucial. Commodities are classified into different classes (Class I through Class IV, and Group A plastics), which determines the fire risk and the necessary sprinkler protection.

• Class I to IV: Non-combustible to moderately combustible materials.

• Group A Plastics: Highly combustible and need enhanced protection.

• Consider factors like packaging materials, pallets, and storage method (rack, palletized, etc.) to classify the commodity correctly.

2. Storage Arrangement:

• How materials are stored impacts fire risk and protection needs. Storage can be palletized, rack storage, or bin box configurations. Shelving types (open vs. solid) also play a role in how sprinklers should be designed and installed.

• Rack Storage: Ensure that there are gaps (called flue spaces) between rows of materials to allow water from sprinklers to penetrate through the racks in case of a fire.

3. Storage Heights and Clearances:

• Pay attention to maximum storage heights and the clearance to the ceiling. The clearance is the space between the top of stored materials and the ceiling. This affects the efficiency of sprinkler systems. Typically, a clearance of at least 18 inches (450 mm) is required between the top of stored items and the sprinkler deflectors.

• For taller storage setups (over 25 feet), in-rack sprinklers may be required for added protection.

4. Types of Sprinkler Systems:

• Control Mode Density/Area (CMDA): Suitable for general storage.

• Control Mode Specific Application (CMSA): For more severe fire risks, such as plastics.

• Early Suppression Fast Response (ESFR): Highly effective for warehouses with high-piled storage, reducing the need for in-rack sprinklers in certain cases.

• Ensure that the sprinkler system matches the commodity class and storage height for maximum effectiveness.

Common Concerns and Caveats

1. Mixed Commodities: When storing mixed types of commodities, protection must be designed for the highest hazard level present. For example, if you're storing both Class I and Class IV commodities together, the fire protection system should be designed for Class IV.

2. Plastic Pallets: Pallets made from plastic pose a higher fire risk than wood. Unreinforced plastic pallets increase the commodity classification by one level, while reinforced plastic pallets increase it by two levels. Be cautious when using plastic pallets in storage environments.

3. High-Volume Low-Speed Fans (HVLS): If your facility uses HVLS fans, they must be installed with specific clearance and interlocked to shut off when a fire sprinkler system is activated. This ensures fans don't interfere with sprinkler water distribution.

4. Column Protection: Building columns within storage racks can obstruct sprinkler water flow. Depending on the storage height, columns may need additional protection, such as sidewall sprinklers.

Practical Identification of Commodities

Class I: Non-combustible materials like metals, stored on wooden pallets or in simple cardboard boxes.

Class II: Non-combustible items in more flammable packaging, such as multi-layered cartons.

Class III: Products made from wood, paper, or natural fibers. May contain small amounts of plastics.

Class IV: Products containing moderate amounts of plastic, either expanded (e.g., foam) or non-expanded.

Group A Plastics: Highly combustible materials like ABS, PVC, polyethylene. These require significant fire protection efforts.

Tips for Industrial Property Owners

1. Know Your Commodity Class: Always verify the class of your stored goods. This can be influenced by not just the product itself but also its packaging and pallet type.

2. Maintain Adequate Clearance: Ensure that storage does not encroach on sprinkler head clearance requirements.

3. Upgrade for Plastics: If storing Group A plastics, especially expanded types, be prepared for more stringent sprinkler requirements.

4. Use Sprinkler Systems that Match Storage Needs: Choosing between CMDA, CMSA, or ESFR systems depends on the type of goods and how they are stored. For high-piled storage or plastic-heavy inventories, ESFR sprinklers are often the best option.

5. Conduct Regular Inspections: Ensure that your sprinkler system is properly maintained, and storage configurations comply with NFPA 13 requirements.

By understanding and applying the general requirements of Chapter 20, industrial property owners can ensure their storage environments are adequately protected from fire hazards, minimizing risks to both their property and their workforce.

Disclaimer:

I am not a certified fire suppression professional. This guide is intended for general informational purposes only to help readers understand key points from Chapter 20 of the NFPA 13 standard. For professional advice, proper fire suppression system design, and compliance with NFPA codes, it is essential to consult with a licensed fire protection engineer or a certified fire safety professional.