Sandwich panels can be produced across a wide thickness range, typically from about 10 mm to 150 mm or more, depending on the manufacturer and the application. The right thickness depends on the structural load the panel must carry, the core material used, and the constraints of the structure in which it is applied. The questions below cover the main factors that determine panel thickness, how core materials influence the choice, and which thickness ranges suit common transport and industrial and transport panel applications.

What determines the maximum thickness of a sandwich panel?

The maximum thickness of a sandwich panel is determined by three main factors: the available production equipment, the structural requirements of the application, and the physical properties of the core material. Most manufacturers set an upper limit based on what their production line can process consistently and accurately.

On the production side, continuous lamination lines have physical limits on the gap between the press rollers or plates. At Compoform, our 72-metre semi-automatic production line can produce panels up to 150 mm thick and up to 13,500 mm long at 2,950 mm wide. That upper limit reflects both the capacity of the equipment and the practical handling requirements of very thick composite panels.

On the structural side, going thicker than the application requires adds weight without delivering useful performance. Engineers specify thickness to reach a given load or stiffness target, not to maximise it. The skin architecture, core density, and span between support points together determine the minimum thickness that meets the requirement. Going thicker than necessary costs money and payload.

What is the standard thickness range for composite sandwich panels?

Standard composite sandwich panels for industrial and transport applications typically range from 10 mm to 50 mm, with the most common configurations between 15 mm and 30 mm. Thinner panels below 15 mm are suitable for light cladding and scaffold planks, while panels above 30 mm are used where high bending loads or thermal insulation requirements call for a greater section depth.

Our own certified product range includes configurations from 11 mm scaffold planks to 30 mm heavy-duty floor panels, with wall panel variants of 17 mm, 20 mm, and 30 mm. These thicknesses reflect the most common structural requirements for truck bodies, trailers, and commercial vehicle interiors. For applications outside this range, custom thicknesses are available.

It is worth noting that “standard” differs by application segment. A scaffold plank operates under very different load conditions than a trailer floor, so a thickness that is common in one context may be excessive or inadequate in another.

Does a thicker sandwich panel always mean better performance?

No. A thicker sandwich panel does not automatically perform better. Greater thickness increases the section depth, which improves bending stiffness and absolute load-bearing capacity, but it also adds weight and material cost. The relationship between thickness and performance depends entirely on the load case, the core material, and the skin specification.

An illustrative example: our 30 mm floor panel carries an average maximum load of 5,647 N in standardised bending tests, compared with 3,240 N for the 15 mm variant. In absolute terms, the thicker panel carries more load. However, the 30 mm panel also weighs considerably more per square metre. For a truck body floor, that extra weight reduces payload, which directly affects the revenue per trip for the operator.

The goal is to find the minimum thickness that meets the structural requirement, not the maximum available thickness. Oversized panels waste material, add dead weight, and, in transport applications, reduce the payload that may legally be carried. In electric trucks and vans, every kilogram of structural dead weight also reduces battery range per charge, making over-specification both a range issue and a payload issue. Procurement teams for electric fleets increasingly treat structural weight as a range variable, not just a cost variable.

How does the core material affect the possible thickness of a panel?

The core material directly determines how efficiently a sandwich panel uses its thickness. A denser or structurally stronger core allows a thinner panel to meet the same load requirement, while a lower-density core may need greater thickness to achieve equivalent stiffness. The core material also influences how the panel behaves under compression, shear, and impact.

PP foam cores

Oriented PP foam cores are available in a range of densities, from 40 kg/m³ to 140 kg/m³. Lower-density foam cores are lighter but less stiff, so panels that use them may need to be thicker to meet a given bending requirement. Higher-density foam cores offer more structural performance at the same thickness, allowing engineers to keep the panel thinner while still meeting load targets. This density range offers considerable flexibility when specifying custom panel configurations.

PP honeycomb cores

PP honeycomb cores of 140 kg/m³ deliver significantly higher compression and bending performance than foam cores of comparable thickness. This makes them the preferred choice for floor panels where concentrated loads from foot traffic, pallet trucks, or vehicle wheels are expected. Because honeycomb is structurally efficient, floor panels can often be kept at 15 mm to 30 mm while still meeting demanding load specifications. The trade-off is a higher surface weight compared with foam-core wall panels of similar thickness.

Which panel thickness is suitable for trucks, trailers, and vehicle bodies?

For truck bodies and trailer applications, the most common sandwich panel thicknesses are 15 mm to 30 mm for floor panels and 17 mm to 20 mm for side walls. Floor panels carry higher concentrated loads and typically use PP honeycomb cores, while side walls prioritise low weight and surface finish and use PP foam cores with PET film skins.

A 30 mm PP honeycomb floor is self-supporting across standard truck body frame spacings, meaning no aluminium subframe is needed beneath it. Removing the subframe eliminates a production step for the body builder and reduces the vehicle’s overall structural weight, freeing up payload. Over a vehicle lifetime of 15 years, a composite floor also eliminates two to three plywood replacement cycles. When you factor in panel costs, installation labour, and vehicle downtime for each replacement, the composite floor is cheaper per year of service, even at a higher unit price.

For electric trucks and vans, the weight argument carries extra force. Lighter body structures extend battery range per charge. Fleet managers specifying electric vehicles in 2026 increasingly ask about structural weight as part of the procurement conversation, not just payload.

Can sandwich panels be produced in custom thicknesses?

Yes. Sandwich panels can be produced in custom thicknesses beyond the standard catalogue configurations. Most specialist manufacturers, including those using continuous lamination processes, can adjust the core thickness to meet a specific structural or dimensional requirement. Custom-thickness production requires a defined load specification and, in most cases, a minimum order volume to justify the setup.

Custom thickness is particularly relevant when a panel must fit within a given envelope, such as a body structure with a fixed internal height, or when a standard thickness over- or under-performs for the application. Specifying the right custom thickness from the start prevents costly redesigns later in the production process.

How Compoform helps you specify the right panel thickness

We work with truck body builders, trailer manufacturers, and vehicle assemblers to determine the panel thickness that meets their structural requirements without adding unnecessary weight or cost. Our standard range covers configurations from 11 mm to 30 mm, and we produce custom thicknesses up to 150 mm for applications that fall outside that range.

When you bring a project to us, we review:

• The load case — floor loads, wall loads, point loads, and distributed loads relevant to your application
• The dimensional envelope — the maximum thickness the structure can accommodate without affecting internal volume or vehicle height
• The weight budget — the structural dead-weight target that protects payload and, for electric fleets, battery range per charge
• The surface requirement — whether the panel needs a finished decorative surface, an anti-slip finish, or a substrate for further processing
• The production process — how the panel integrates into your assembly line, including cutting to size, edge treatment, and joining methods

Our panels are 100% European-made at our sites in Beek and Ospel, the Netherlands, and are available in custom sizes up to 13,500 mm × 2,950 mm. We cut panels to your exact specification, so you receive parts that are ready for assembly rather than sheet material that requires further processing.

If you are specifying panels for a truck body, trailer floor, or commercial vehicle application, talk to our engineering team today before you finalise your design. We review your configuration, flag potential issues, and optimise the panel specification for your assembly process before production begins.

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