Mezzanine Component Glossary

Mezzanine Baseplates are a steel plate welded to the bottom of each mezzanine column, sandwiched between the column and the concrete floor of your building. The baseplate distributes the weight of the mezzanine and its load over a wider area than possible by the columns alone, preventing point-loading on the slab.

Baseplates are pre-drilled for anchor bolts, with a common minimal size being 12″ x 12″ x 3/4″ thick. Undersized or improperly seated baseplates can cause excessive mezzanine movement.

Mezzanine Girders are the primary horizontal beams that span between the column, forming the main structural skeleton of the mezzanine. Girders carry the cumulative load from the joists and decking and transfers said load into the columns. They are typically fabricated from wide-flange structural steel sections.

Column Connection Joists are a style of joist that frames directly into a column rather than into a girder. These members provide a structural tie between columns at the joist level, adding lateral stability and allowing the deck to be supported in areas adjacent to columns. Connections are made via factory-welded shear connectors or bolted cleats attached to the column flange or web.

I-Beams are the principal structural beam of a mezzanine, featuring an I-shaped (or H-shaped) cross-section composed of two horizontal flanges connected by a vertical web. I-beams offer a high strength-to-weight ratio and are used as the main girders for small-to-medium spans, supporting the full load path from the deck through the joists and down into the columns. Mezzanines utilizing I-Beam Mains are referred to as I-Beam and Truss Mezzanines.

Cold-Rolled Beams are structural members formed by bending sheet metal at room temperature into C-channel profiles. In a mezzanine system, cold rolled beams attach to tubular steel or tapered columns and serve as the supporting framework for the floor. They are significantly lighter than hot-rolled structural steel, which reduces shipping costs and simplifies installation — making them ideal for light-duty mezzanine applications. A mezzanine making use of cold-rolled beams may also be referred to as a roll-form mezzanine.

B-Decking is a type of corrugated steel decking panel with a 1.5″ deep rib profile, commonly used as the structural subfloor of a mezzanine. B-Deck offers a high strength-to-weight ratio, is available in various gauges and finishes (galvanized, painted, or coated), and provides the load-bearing surface onto which a finished floor material (such as resin board or plywood) is placed. It is the most common metal decking type in the mezzanine industry.

Resin Decking refers to an industrial-grade engineered wood composite flooring panel (commonly the brand ResinDek®) installed on top of the B-Deck subfloor. Resin deck panels provide a smooth, durable walking and rolling surface, can save up to 34% in overall cost per square foot compared to a concrete deck, and are available in varying thicknesses and laminate finishes for different load and wear requirements.

Mezzanine hand railings refer to a safety guardrail system installed around the open edges of a mezzanine platform to prevent falls. Hand railing typically consists of a top rail, one or more mid-rails, and vertical posts, meeting OSHA or local building code height requirements (generally 42″ high). It provides a continuous barrier that protects workers and visitors at the mezzanine level. Another part of the hand railing system in a mezzanine is mezzanine gates, which provide forklift access to a mezzanine as-needed without compromising on employee safety when open access to upper mezzanine levels are not necessary.

The primary access and egress systems that allow personnel to safely travel between the ground level and the mezzanine platform. Mezzanine stairways are prefabricated steel stair systems available in straight, switchback, or L-shaped configurations, designed to meet ANSI MH28.3 and OSHA §1910.25 requirements for tread depth, riser height, and width.

Where floor space is limited, a ships ladder; a steep, fixed stairway set at a 50°–75° incline with open risers and treads (minimum 4″ deep × 18″ wide) may be used as an alternative or secondary means of egress.

Both stairways and ships ladders are required to be fitted with continuous guard rails along their length, consisting of a top rail at 42″ above the walking surface, one or more mid-rails limiting clear openings to no more than 10 1/2″, and vertical posts capable of withstanding at least 200 lbs of force in any direction.

Guard rails also extend around the full open perimeter of the mezzanine platform itself, integrating seamlessly with the stairway railing to form an unbroken fall-protection barrier that meets OSHA and IBC compliance standards.

Mezzanine Catwalks are narrow, elevated walkway platforms designed to provide worker access above or between rows of racking, shelving, conveyors, or equipment on the facility floor. Unlike a full mezzanine deck, a catwalk covers only the aisle or pathway area needed for foot traffic and order picking, making it a more cost-effective solution when a complete platform is unnecessary. Catwalk mezzanine systems are commonly integrated into pick modules, where suspended walkways attach to first and second-level shelving, optimizing traffic flow while preserving valuable floor area for material handling below. Load specifications and safety requirements are governed by OSHA §1910.21–22 and local building codes.

Vertical Reciprocating Conveyors (Also known as Vertical Lifts) are a type of specialized material-handling lift that moves products, materials, and equipment vertically between mezzanine levels, balconies, basements, or multiple stories of a building. A VRC uses a guided carriage or platform that travels up and down along vertical mast columns, powered by either a hydraulic cylinder system or a mechanical chain-drive mechanism. Unlike an elevator, a VRC is classified strictly as a freight conveyor and is not rated for passenger use; Vertical Lifts are only rated to transport pallets, boxes, totes, hardware, tools, material handling equipment such as forklifts, and other cargo only. VRCs provide fast, efficient access to and from mezzanine platforms and can be installed through-floor, in an unused elevator shaft, in interior/exterior configurations, or simply installed within a wire security cage anywhere that it is safe and convenient for your mezzanine configuration. They are governed by ASME B20.1 conveyor safety standards rather than elevator codes, which typically results in lower installation and permitting costs.

A Mezzanine (also known as a Work Platform) is an intermediate floor constructed between two levels of a building, whether that be between the two main stories or between the floor and ceiling of a single high-ceilinged space, that does not extend over the entire footprint of the area below. The term derives from the Italian word mezza, meaning “half” or “middle.” In industrial and commercial settings, a mezzanine is a freestanding elevated steel platform supported by its own columns, girders, and joists, engineered to create additional usable square footage for storage, office space, production, or order fulfillment without expanding the building’s exterior walls. Under the International Building Code (IBC §505), a mezzanine is defined as an intermediate level between the floor and ceiling of any story and is typically not counted as a separate floor of the building.

A Rack Supported Mezzanine is an elevated platform that uses structural pallet racking frames rather than independent steel columns as its primary vertical support system. The mezzanine deck is built directly on top of the existing rack uprights, creating a second (or third) level of usable floor space while preserving pallet storage positions below. This design saves material cost and installation time compared to a freestanding structural mezzanine, and it maximizes warehouse cube utilization by converting otherwise unused vertical space above the racks into walkways, picking aisles, additional storage, or work platforms. Options commonly include stair towers, catwalks, guard railing, and pallet drop areas.

A Shelving Supported Mezzanine is a multi-level storage structure in which industrial shelving units — rather than pallet racks or freestanding columns — serve as the structural base supporting the upper platform. A deck can be placed on top of the shelving to create a level walking surface for a full mezzanine floor, or additional shelving units can be stacked on the base level to increase storage density while maintaining the same footprint. Shelf supported mezzanines are ideally suited for facilities handling smaller, lighter inventory that is picked by hand, and catwalks are typically built between shelving aisles to provide worker access on the upper level.