Disclaimer: The following article is based on research conducted during a prior role in modular product development. It reflects independent reasoning and public-domain insight only, and does not disclose any proprietary company data or performance claims.
The Challenge: Uncharted Territory
“We need to do Fire safety for our mezzanine. The demands for compliance is increasing.”
It was one line, casually delivered—but layered with complexity. I hadn’t designed a mezzanine structure before. And fire safety? That was a field I’d never been trained in. But I do think in systems. And I understand when responsibility exceeds clarity. So I accepted the task—with no illusions and no shortcuts. I faced the daunting prospect of navigating complex regulations, diverse stakeholder expectations, and the intricacies of mezzanine structures.
Building the Knowledge Base
Recognizing the knowledge gap, I embarked on an intensive self-education journey:
- Fire Dynamics: Understanding the behavior of fire, including ignition, spread, and suppression mechanisms.
- Regulatory Frameworks: Studying various fire safety codes and standards, such as EN 13501-1/2, NFPA, and local building regulations.
- Mezzanine Structures: Analyzing the components and configurations of mezzanine systems to identify potential fire hazards.
This foundational knowledge was crucial in framing the problem and identifying potential solutions. The more I read, the more I understood that this wasn’t a materials exercise. It was first a scope definition problem and then more.
Problem 1 : Scope and Control
Mezzanines are widely used in logistics, warehousing, and light industrial facilities for their ability to unlock vertical space. But their integration into fire safety strategies is often inconsistent, oversimplified, or treated as someone else’s problem. Unlike permanent structural floors, mezzanines sit in a unique regulatory and technical zone—not always subject to the same fire resistance requirements, and often installed by vendors who have limited control over active safety systems in the building.
Hence, The fire safety of mezzanine systems not as a one-time design decision, but as a multi-layered systems problem—requiring both design clarity and regulatory alignment.
Problem 2: Mezzanines are heterogenous, not just steel
Mezzanines are composed of: -
- Primary structural elements (steel columns, beams, bracing)
- Decking materials (particle board, plywood, grating)
- Guardrails, staircases, pallet gates
- Optional integrations (robotic conveyors, lighting, partitions)
Fire affects each of these layers differently. Worse, mezzanines typically lack inherent fire compartmentation, often sit in open-plan environments, and frequently depend on surrounding infrastructure (e.g., sprinklers, smoke extract) that the mezzanine vendor neither specifies nor controls.
In short: they don’t fail as components, they fail as systems—which makes clarity in responsibility and performance essential.
Problem 3: Classification Depends on the Tested System
Fire safety classifications can be misleading if separated from the test method and the construction assessed. Reaction-to-fire describes how a material contributes to fire, while fire resistance refers to how an element maintains its function over time. These results cannot be directly applied to different profiles, fixings, build-ups, or jurisdictions. For mezzanines, classification must be checked against the exact product, full assembly, intended use, and local approval requirements
Common misunderstandings include :
- Fire-resistant does not mean fire-safe in all use cases. Fire retardant is not fire resistance. Fire rated terms are based on place where products are tested and the testing method itself.
- A certified board or casing system in one jurisdiction (region) may not be approved in another unless tested as part of the final assembly.
- Certificates given to products often highlight the product, not the configuration, which is where failures occur
- A single product may have a higher class for fire rating than a combination of two materials, which usually reduces the fire rating. A steel unit or a floor casing may have a higher rated fire class but combine them together and there is a different system.
Problem 4: Structural Profile Challenges: Not All Steel Behaves the Same
A key fire safety blind spot lies in how we treat steel profiles based on the type and the purpose they serve.
- Both hot-rolled and cold-formed profiles are used in mezzanine systems. They have different thermal behaviors and intumescent coatings may not perform identically across these types. Thinner profiles often reach critical failure temperatures faster. Most passive protection systems are tested on hot-rolled shapes. Without compatible testing, applying the same product to thinner profiles risks false equivalence.
- There is no one solution fits all. Fire protection casings for one and intumescent coatings for another in the same mezzanine system can work wonders for a mezzanine system.
- Compartmentation of the entire system might work on one mezzanine system but for others you need to divide the mezzanine system into different compartments. This division is often based on the local regulation and decision of fire safety auditor
Engineers and specifiers must verify product compatibility with the actual profile geometry—not just rely on fire rating tags.
Problem 5: Stakeholder Identification and Responsible Assignment
Effective fire safety in mezzanine systems depends not only on the right technical interventions, but also on clearly defining who is responsible for what—at every stage of the project.
Mezzanines frequently cross multiple domains: structural, logistical, operational, and regulatory. Without formal role separation and coordination, fire safety responsibilities become fragmented—especially when different parties assume that someone else has “covered it.”
Below is a breakdown of key stakeholders and their typical roles in the fire safety process:
- Mezzanine vendor or manufacturer: They should be responsible for specifying and supplying rated materials (e.g., casings, boards), documenting their technical performance limits, and aligning claims with jurisdictional fire safety requirements. The inherent risk carried is overstating system-level fire safety or omitting regional approval differences that may render certain materials non-compliant at the project level.
- Building owner or client: They should be typically responsible for the overall fire strategy at the site, including integrating the mezzanine into suppression systems, coordinating evacuation pathways, and ensuring proper occupancy classification. A frequent risk is assuming that the mezzanine supplier has addressed full compliance when in fact only component-level protection was included.
- Fire safety consultant or engineer: They are usually tasked with evaluating the mezzanine as part of the building’s fire performance strategy, including compartmentation, suppression compatibility, and REI rating requirements. When engaged too late in the project, their role is often reduced to sign-off rather than substantive input—weakening the integration of mezzanine-specific risks into the broader fire model.
- Architect or building designer for the industrial space: They must ensure that mezzanine locations do not obstruct evacuation flow, that access points are appropriately distributed, and that spatial relationships are maintained for effective smoke and heat management. The primary risk is assuming generic mezzanine layouts do not require contextual adjustment for specific fire loads or building geometry.
- Installer or subcontractor: They are responsible for assembling the fire-rated elements exactly as specified—whether that involves mounting casing systems, installing compliant decks, or ensuring spacing tolerances. A key risk is material substitution or procedural shortcuts during installation, which can invalidate fire certification if undocumented.
- Local Authority Having Jurisdiction (AHJ): The AHJ reviews project documentation and validates site compliance under the relevant fire safety regulations. Miscommunication often occurs when manufacturers submit global product certificates without matching them to local regulatory conditions, leading to delayed approvals or rework.
- Warehouse operators or facility managers: They are responsible for upholding safety practices post-installation, including maintaining clear egress paths, preventing storage against protected structural elements, and ensuring fire signage remains visible. Their most common risk is layout drift—unintended changes that nullify original fire assumptions, such as placing combustible goods near structural columns or blocking secondary exits.
These stakeholders can be third party, client and their hired advisors and the vendor and their associates. Hence this is how one can make a good coordination strategy based on the contractual agreements.
- A responsibility matrix should be developed at the outset of the project to define who is accountable for each fire safety intervention.
- Interface documentation between the product vendor and the site fire engineer should detail where modular responsibility ends and system-level planning begins.
- A post-installation change control process should be implemented to track operational modifications that may introduce new fire risks or invalidate installed protection.
Solution Strategy: Assigned Responsibility
A Tiered Fire Strategy for Mezzanine Systems: This includes three levels of intervention where you have vendor and their engineers, a joint responsibility of vendor and client (or their system integrator), client specific
- Base-Level Protection (Vendor-Controlled) - Casing systems for columns - Decking with certified fire reaction performance - Edge fascia and barriers
- Interface-Level Planning (Joint Responsibility) - Alignment with sprinkler coverage - Marking storage-free zones near supports - Interface documentation
- Site-Specific Enhancement (Client-Controlled) - Fire-rated stairs - Compartmentation planning - Assembly-tested solution.
Design Recommendations for Engineers and Specifiers: Some key points that must be considered while designing a mezzanine system when the contract also include fire safety system are as follows:
- Match passive systems to profile thickness and behavior; do not assume coatings designed for hot-rolled steel will suffice.
- Confirm local acceptance of fire ratings.
- Use rated boards for decking and check if the fire rating is for both sides or one. Where possible, use rated boards with low smoke and no-drip ratings; document test method.
- Clarify vendor vs. site system (client) responsibilities.
- Plan for layout changes and maintenance if only included in contract scope when maintenance responsibility is also involved.
- Account for likely changes in stacking, robot paths, or wall additions post-handover.
- Always suggest hiring an expert to client when quotation is given as these are not fire safety regulations but a possible solution.
Conclusion
This strategy outlines a structured, system-aware approach to mezzanine fire safety—one grounded in regulatory logic, component compatibility, and passive design prioritization. While it provides a clear foundation, future iterations would benefit from added layers: use-case differentiation (e.g., storage vs. occupancy), regional approval mapping, cost-impact tradeoffs, and visual tools to support faster decision-making. Fire strategy in modular systems is not a checklist—it’s a coordination challenge. Continued work should aim to refine this into a more comparative, context-specific framework that helps stakeholders act—not just understand.