It used to be easy to think of seismic bracing as something California contractors worried about. The building codes have been moving in a different direction for years. The International Building Code, which governs construction across most of the United States, incorporates ASCE 7 seismic provisions that apply to non-structural components in facilities across a much wider geographic footprint than most people assume. Data centers, hospitals, manufacturing facilities, and distribution centers in the Midwest, Southeast, and Mid-Atlantic all have seismic design requirements for the equipment and support systems installed inside them.
For OEMs whose products go into these facilities, seismic compliance is increasingly a specification requirement rather than a regional concern. Understanding how Unistrut's system supports certified seismic assemblies, and what that means for your product design and documentation, is becoming a more common part of the conversation with end users and specifying engineers.
What the Codes Actually Require
Seismic design requirements for non-structural components flow primarily from ASCE 7, which the International Building Code adopts by reference. The requirements specify that non-structural components, including equipment supports, overhead framing, conduit, piping, and mechanical systems, be designed and braced to resist seismic forces appropriate to the facility's seismic design category.
Seismic design categories run from A through F, with A representing the lowest seismic hazard and F the highest. Category D, E, and F facilities, which include essential facilities like hospitals and emergency operations centers in moderate to high seismic zones, have the most stringent requirements. But even Category C facilities, which cover a broad range of commercial and industrial buildings in lower seismic hazard areas, have non-structural bracing requirements that affect how equipment support systems need to be designed.
The component importance factor is another variable that affects how stringent the requirements are. Life-safety components, including fire suppression systems, emergency power, and equipment in healthcare facilities, carry an importance factor of 1.5, which increases the calculated seismic force those components must resist. Standard occupancy components carry a factor of 1.0. The difference matters when you're sizing bracing members and connections.
For OEMs, the practical implication is that if your equipment goes into a facility that has seismic design requirements, and your product includes overhead support structures, equipment frames, or attached support systems, your design may need to address seismic loading. And your customer, or their structural engineer of record, may ask for documentation that it does.
Why Unistrut Is Well-Positioned for Seismic Applications
Unistrut has a long history in seismic bracing applications, and the system's characteristics are well-suited to the requirements these applications impose.
The most significant credential is OSHPD pre-approval. OSHPD, the Office of Statewide Health Planning and Development, is the California agency that governs healthcare facility construction and is broadly considered the most rigorous seismic standard-setting body in the country. Unistrut's seismic bracing systems carry OSHPD OPM pre-approval, which means they've been reviewed and accepted for use in California healthcare facilities, the most demanding seismic application environment in the US.
As USC's own seismic bracing page notes, although the OSHPD OPM approval is specific to California, it's recognized nationally as a mark of engineering rigor. Specifying engineers outside California who see OSHPD pre-approval on a seismic bracing system understand what that means.
Beyond the approvals, Unistrut's channel system has physical characteristics that lend themselves to seismic bracing design. The continuous slot allows brace attachment points to be positioned where the geometry of the bracing design requires, not just where pre-drilled holes happen to fall. This is particularly valuable in complex installations where the exact bracing angle and attachment location are determined by the installed configuration of the supported system rather than by a fixed template.
The modular fitting system allows seismic brace connections to be made with purpose-built hardware rather than field-fabricated connections. P1546 and P3810 fittings, among others, are commonly used in seismic bracing configurations, providing engineered connection capacity that can be calculated and documented rather than estimated.
How Seismic Requirements Affect OEM Product Design
For OEMs whose products include integrated support structures, overhead mounting systems, or equipment frames intended for installation in facilities with seismic design requirements, the implications are design-level, not just procurement-level.
Seismic bracing in a Unistrut system typically requires longitudinal and transverse bracing at defined intervals. For overhead systems, bracing in both horizontal directions resists the lateral forces a seismic event generates. The specific brace spacing, member sizing, and connection details depend on the seismic design category of the facility, the weight of the supported equipment, and the height of the installation above grade.
This is design work that benefits from engineering input. Unistrut's seismic design guide, which is available through USC, provides tables for seismic factor of 1.0g that allow brace location, member sizes, and anchorage requirements to be determined for standard configurations. For seismic factors other than 1.0g, a new seismic table is required and should be reviewed by a qualified engineer. USC can discuss the appropriate level of engineering support for your specific application, recognizing that the scope of that support and whether it involves a paid engineering engagement depends on the complexity and scale of the program.
For OEMs designing products that will be deployed across multiple facilities with varying seismic design categories, designing to the more stringent requirements from the start provides a product that qualifies everywhere, rather than requiring separate design documentation for different installation environments. That upfront investment in seismic-capable design pays back in reduced friction at the point of sale and installation.
Documentation: What Customers and Engineers Will Ask For
When a specifying engineer or facilities team is evaluating equipment for a seismically sensitive application, they're looking for documentation that answers specific questions.
Does the support system have engineered seismic capacity? Unistrut's published load tables, engineering catalog, and OSHPD pre-approval documentation provide the foundation for answering this question. For OEMs incorporating Unistrut framing into their products, referencing these resources in your product documentation gives specifying engineers the information they need without requiring custom calculations for every installation.
Has the design been reviewed by a qualified engineer? For projects where the structural engineer of record requires documentation of the support system design, USC's PE stamp service provides a documented engineering review. As with other engineering services, the scope and cost of PE stamp support depends on the application and is something USC's team can discuss based on your specific program.
Does the installation comply with the applicable building code? Compliance documentation for OSHPD, IBC, and ASCE 7 seismic requirements is ultimately the responsibility of the project's engineer of record and the installing contractor. What USC and properly documented Unistrut assemblies provide is the product-level foundation that makes that compliance demonstrable. The structural engineer still needs to verify that the support structure itself, the deck or structure the Unistrut system is attached to, can carry the loads the seismic bracing generates. That's a project-specific determination that no pre-engineered system can make on its own.
Where This Is Heading
Building codes continue to expand seismic design requirements geographically and across more building types. As the IBC continues to be adopted more broadly and ASCE 7 provisions become more widely enforced, the number of OEM customers who need to ask seismic compliance questions about their equipment and support systems will grow.
OEMs who are already thinking about seismic design in their product development process are ahead of that curve. Those who are waiting for a customer to ask the question before considering it will find themselves in reactive mode at a point in the sales process where it's harder to respond quickly.
Unistrut's established seismic credentials, and USC's ability to support the documentation and engineering conversations that seismic compliance requires, make this an area where the supplier relationship adds genuine value beyond material supply.
The Most Important Part is Your Custom Part. When that part needs to perform in a seismic event, and more of them do than most OEMs realize, building with a system that has the engineering credentials and documentation to back it up is the right foundation. Contact the USC team to discuss seismic compliance requirements for your application, or visit our services page to learn more about our engineering and documentation capabilities.