Seismic Racking Requirements: What Warehouses Outside California Still Need to Know

Seismic racking isn’t just a California problem. 

Many warehouse managers assume seismic rack design only matters in California. If your facility isn’t near the San Andreas Fault, it’s easy to think earthquakes aren’t part of your racking decisions.

But that assumption is outdated and, more and more often, wrong.

Seismic considerations apply across much of the United States now, and building codes now require seismic design in many regions outside traditional earthquake zones. Even mid-level seismic events can create powerful lateral forces that pallet racking wasn’t originally designed to handle. Because racks are tall, narrow structures carrying heavy loads high above the floor, those forces can cause serious stability risks.

In this article, I’ll explain why seismic rack design matters outside California, what building codes require, and what warehouses should evaluate when installing or modifying pallet racking systems.

Why Seismic Design Matters for Warehouse Racking

Pallet rack systems are tall, narrow steel structures built to support thousands of pounds of inventory high above the floor. Under normal conditions, they primarily handle vertical loads — the weight of pallets, products, and the rack components themselves.

But earthquakes introduce a very different challenge: lateral forces.

Instead of pushing straight down, seismic motion causes racks to sway from side to side. Without the right engineering, that movement can cause racks to tip, shift, or collapse progressively from one bay to the next.

The consequences can be catastrophic. Rack failures during seismic events can:

• Injure workers
• Destroy large amounts of inventory
• Shut down operations for days or weeks

Even moderate earthquakes can damage rack systems that were never designed to handle lateral stress.

That’s why we have seismic design. At its core, it protects people, product, and operational continuity by making sure racking systems remain structurally stable when the ground moves.

Why Warehouses Outside California Still Need to Care

You’re at risk for earthquakes across the U.S. — not just along the West Coast. California receives the most attention, sure, but seismic activity also happens in regions like the New Madrid fault zone in Missouri, parts of Utah, South Carolina, and even areas of New York.

Modern building codes reflect this. Instead of using simple regional “seismic zones,” today’s codes rely on site-specific seismic data to determine design requirements. In some cases, two warehouses in the same state — or even the same city — might have different seismic design requirements based on soil conditions, building characteristics, and location.

And many cities now enforce seismic rack design through permitting and engineered drawings. Insurance carriers are also paying closer attention to compliance when they evaluate risk.

In other words, seismic compliance is a national expectation more and more every year — not just a California requirement.

The Building Codes That Drive Seismic Rack Design

Several building and engineering standards determine how pallet racking has to be designed in seismic conditions. The most common framework starts with the International Building Code (IBC). Many states and municipalities use this as their foundation for structural requirements.

Seismic design calculations typically follow ASCE 7. That’s the engineering standard that defines how structures must resist earthquake forces. And for pallet racking specifically, the Rack Manufacturers Institute (RMI) publishes ANSI/RMI MH16.1. This standard outlines structural design standards for industrial steel storage racks.

Ultimately, though, local building departments and fire authorities enforce these requirements. In many places, pallet racks are treated as building-like structures rather than simple equipment. That’s why racks above roughly six to eight feet fairly often require permits, as well as engineered drawings and structural calculations to make sure you’re actually in compliance.

To sum all that up simply: Rack compliance depends on the specific location of your facility, not just the specifications the rack manufacturer provides.

Core Components of Seismic Rack Design

Seismic rack design isn’t about one upgrade or one stronger part. It’s about strengthening the entire system so it can handle both vertical loads and lateral movement during an earthquake.

One of the most important parts of this is anchoring. Rack anchors have to resist both shear forces and uplift forces from ground motion. That means you need proper:

• Embedment depth
• Anchor type
• Torque

Those are all critical to keeping your system secured to the concrete slab.

Base plate design also matters here. Larger baseplates distribute seismic forces more effectively into the floor. That cuts stress at the column base.

And within the rack frame, diagonal bracing increases lateral stiffness and helps you prevent excessive sway. At the same time, beam-to-upright connections have got to remain engaged under vibration and dynamic loading.

Finally, load distribution plays a role. This one’s simple: Uneven or off-center loads increase stress during seismic events.

Larger baseplates distribute seismic forces more effectively into the floor. That cuts stress at the column base.

Why Rack Configuration Matters for Seismic Performance

Hardware isn’t the only thing that determines seismic performance. Rack configuration is going to play a major role in how well a system responds to lateral forces.

Several warehouse layout factors influence seismic behavior:

• Rack height
• Beam spacing
• Frame depth
• How your racks are arranged within a row

For example, back-to-back rack rows tend to give you more lateral stability than single-row configurations because the connected frames help resist side-to-side movement.

Beam spacing also matters. Wider spacing between beam levels increases the unsupported length of the upright columns. That can reduce structural capacity under both vertical and lateral loads. Similarly, storing heavier products on upper levels raises the system’s center of gravity, which also increases stress during seismic motion.

Even small adjustments — like raising the first beam level to give you more floor clearance — can change frame capacity a lot.

The key point is that seismic performance depends as much on how racks are configured as on the components themselves.

Common Seismic Compliance Mistakes Warehouses Make

Many seismic compliance issues come from small shortcuts you take early in a project.

One common mistake is installing racking without engineered seismic calculations. A system that works in one region may not meet requirements in another. Relocating rack from one facility to another without re-engineering can create the same problem.

Anchoring is another common issue. Using insufficient anchors — or installing them incorrectly — can undermine your entire system’s stability. Reconfiguring beam elevations without reviewing updated capacity calculations can also affect seismic performance.

Some facilities purchase low-quality racking that doesn’t meet local code requirements. While the upfront savings may look appealing, the system may fail inspection or call for expensive retrofits later.

These are extreme cases, but I’ve seen municipalities require racks to be removed or upgraded after failing compliance checks.

Retrofitting Existing Racking for Seismic Compliance

Many older warehouses were built before current seismic design standards were widely enforced. As codes evolve and inspections become more in-depth, your facility may need upgrades to bring your current racking systems into compliance.

Common retrofits include: 

• Installing stronger anchors
• Upgrading to larger baseplates
• Adding additional bracing
• Reinforcing rack frames

In some cases, you may need to re-engineer the rack configuration itself to meet current seismic design requirements.

Regular inspections are also important. Periodically check anchor integrity, verify that frames remain plumb, and confirm that load capacity signage reflects the actual rack configuration.

How East Coast Designs Seismically Compliant Rack Systems

At East Coast Storage Equipment, seismic design begins with understanding the exact conditions of your facility. That includes reviewing your warehouse location, local seismic data, and the specific rack configuration planned for your space.

We work with engineers to produce stamped drawings and structural calculations that meet applicable building and fire codes. The design process includes specifying appropriate anchors, baseplates, bracing, and other components required for seismic performance.

Just as important, we make sure configuration details like rack height, beam spacing, and load placement remain compliant with the engineered design.

The goal is simple: Install rack systems that pass permitting, protect your workers and inventory, and remain structurally stable throughout the life of the installation.

Seismic Design Is Just Good Rack Design

Seismic racking requirements are no longer limited to California. Modern building codes use location-specific seismic data, which means warehouses across much of the country have to consider earthquake forces when designing or installing pallet rack systems.

But seismic design protects more than just compliance. It protects your workers, inventory, and your warehouse operations.

Ready to build a compliant, efficient, and future-proof warehouse system? We’re ready to help. Contact East Coast online or call 888.294.5022 to get started.