Mezzanine Floor Decking
Written by David Moore, mezzanine floor specialist at Western Industrial
Resource Highlights
Mezzanine Floor Decking
Mezzanine floor decking is the structural surface that spans between the secondary steel joists of the mezzanine frame to create the upper floor platform. It carries the loads from the upper level, goods, equipment, furniture and people, and transfers them into the secondary joist grid below.
The decking type for a mezzanine floor is chosen from the operational requirements of the upper level: what will be stored or happen on the deck, what surface properties are needed, and what loads will be applied. The structural chipboard that is standard for office and storage mezzanines is entirely different from the steel mesh used in industrial and drainage environments, or the chequer plate specified for machinery areas.
Western Industrial specifies and supplies the correct mezzanine deck type for every installation. Contact us to discuss your project.
Mezzanine Decking Types
P5 moisture-resistant chipboard: the standard
P5 chipboard at 38mm thickness is the standard mezzanine deck board for storage, warehouse, office and retail mezzanine floors across the UK. It is the correct specification for almost all commercial and light industrial applications and is the deck type most buyers are referring to when they ask about mezzanine floor decking.
P5 denotes the board’s performance classification under EN 312, it is a load-bearing board for use in humid conditions. The moisture-resistant property is important in warehouse and storage environments where condensation, cleaning or occasional water ingress may occur. At 38mm, P5 chipboard spans safely between secondary joists at the standard 600mm centre-to-centre spacing without excessive deflection under storage loads.
P5 chipboard decking is laid in a staggered (brick-bond) pattern to avoid continuous joints at secondary joist positions. Boards are fixed to the secondary joists using self-tapping screws at the perimeter and at intermediate joist positions. The surface of P5 chipboard accepts all standard commercial floor finishes: carpet tile, vinyl, LVT, raised access flooring and ceramic tile.
Indicative cost: P5 chipboard decking is typically included in the standard mezzanine floor package price. As a standalone supply item, 38mm P5 chipboard is approximately £8 to £12 per m² for materials, before fixing.
Read more about office mezzanine flooring finishes here.
Steel open mesh flooring
Steel open mesh flooring, also known as open grid flooring, bar grating or metal deck, is specified where the deck must allow drainage, ventilation or light transmission through the floor surface. The mesh consists of bearing bars welded to cross bars at regular intervals, creating an open grid that is walkable but allows liquids and debris to pass through.
Open mesh flooring is used in food production and processing environments where hygiene and drainage are essential, in mezzanines above machinery where oil or coolant spray needs to drain away from the deck surface, in plant mezzanines where ventilation airflow must pass through the floor, and in some industrial environments where a non-combustible deck is required.
Steel mesh flooring is heavier than chipboard and adds more dead load to the secondary joist design. It is non-combustible, which may simplify the fire protection assessment in some industrial environments. The open surface is slip-resistant when wet but not recommended for wheeled traffic (trolleys, pallet trucks) without plating over the wheel paths.
Steel chequer plate
Steel chequer plate (also called tread plate) is a solid steel plate with a raised diamond pattern on the upper surface that provides grip and slip resistance. It is specified for mezzanines where the deck is subject to vehicle traffic (pedestrian only, not fork trucks), heavy point loads from machinery feet, or where a robust, long-life industrial surface is required.
Chequer plate is significantly heavier than chipboard, typically 4mm to 6mm steel plate adds 32 to 48 kg/m² in dead load, and this additional self-weight must be included in the structural calculations. It is more expensive than chipboard and adds considerable weight to the secondary joist design, so its use is normally limited to areas where the operational requirement specifically demands it.
Flowforge open bar grating
Flowforge grating (manufactured by Lionweld Kennedy or similar suppliers) is a swaged steel bar grating where the bearing bars are deformed to lock the cross bars in position without welding. The result is a lighter, open grating suitable for applications where some drainage is needed but a finer surface aperture than standard open mesh is preferred.
Flowforge is used in some industrial mezzanine applications, particularly in the automotive and engineering sectors where it is a familiar material. It is also used in some plant room and access platform applications. Like open mesh, it is not suitable for wheeled traffic without wheel-path plating.
Resin-coated concrete board
For mezzanine floors in food preparation, catering, commercial kitchen or wet-area environments, a resin-coated concrete board (sometimes referred to as cement particle board) provides a dense, hard-wearing, impermeable deck surface that can withstand regular wet cleaning and chemical cleaning agents.
Resin-coated board is heavier than chipboard and more expensive. It is typically used in conjunction with anti-slip resin or epoxy flooring applied over the top, creating a seamless, hygienic and fully cleanable floor surface. This specification is standard in commercial kitchen mezzanines, food production environments and some retail food service applications.
| Deck Type | Approximate Weight | Typical Material Cost | Best Suited For |
|---|---|---|---|
| P5 Chipboard (38mm) | 14 kg/m² | £8–£12/m² | The standard choice for storage, warehouses, offices and retail mezzanine floors. Suitable for the vast majority of commercial applications. |
| Steel Open Mesh (25 × 3mm) | 12–18 kg/m² | £35–£55/m² | Ideal for food production, plant rooms and environments requiring ventilation, drainage or light transmission through the deck. |
| Steel Chequer Plate (4mm) | 32 kg/m² | £45–£65/m² | Designed for machinery platforms, heavy industrial environments and areas subject to high impact or vehicle traffic. |
| Flowforge Bar Grating | 10–15 kg/m² | £40–£60/m² | Commonly specified for engineering facilities, automotive workshops, maintenance platforms and plant access areas. |
| Resin-Coated Concrete Board (18mm) | 26 kg/m² | £25–£40/m² | Well suited to food service, catering, commercial kitchens and wet areas, typically finished with an anti-slip resin or epoxy coating. |
[Costs are materials-only indicative figures. Installation and fixing are additional. All figures 2026.]
How mezzanine decking affects structural design
The deck type selected affects the structural design in two ways: dead load and span capability. P5 chipboard at 38mm is designed to span 600mm between secondary joists, the standard joist spacing. If the deck type is changed to a heavier material (steel mesh, chequer plate), the additional dead load must be added to the structural calculations. If a lighter deck is used at wider joist spacing, the structural adequacy of the deck itself must be checked.
For the majority of projects, P5 chipboard at 38mm on 600mm joist centres is the correct and most economical specification. Deviations from this standard require specific structural assessment.
Read more about mezzanine floor load capacity here.
