What are the benefits of sandwich panels over steel and wood?

Compoform · 26 Jul 2026

Sandwich panels outperform steel and wood on the criteria that matter most to manufacturers: weight, durability, corrosion resistance and total cost of ownership. A thermoplastic sandwich panel with a PP honeycomb or PET foam core and glass-fibre-reinforced skins delivers structural performance comparable to steel at a fraction of the weight, and lasts far longer than wood in demanding transport and industrial environments. The questions below explain each of these advantages in detail.

How much weight do sandwich panels save compared with steel and wood?

A thermoplastic sandwich panel is considerably lighter than an equivalent steel panel and noticeably lighter than plywood of comparable thickness. In commercial vehicle and industrial panel applications, switching from steel or wood to a composite sandwich panel can significantly reduce structural weight, depending on the specific configuration and application requirements. That weight saving translates directly into extra payload or, in electric vehicles, a longer range per charge.

For truck body builders and trailer manufacturers, every kilogram saved on the body structure is a kilogram that can carry revenue-generating cargo. In 2026, this argument has a second dimension that procurement teams increasingly raise: lighter body structures extend the range of electric trucks and vans. Every kilogram of structural dead weight reduces range per charge, making weight reduction a range argument and not only a payload argument. EV fleet buyers now treat this as a standard procurement request.

The weight advantage of sandwich panels comes from their structural logic. A lightweight core, whether oriented PP foam or PP honeycomb, separates two thin, highly stiff glass-fibre layers. This geometry delivers high bending stiffness relative to mass — the same principle that makes an I-beam stiffer than a solid bar of the same weight. The result is a panel that carries substantial loads without the mass penalty of solid steel or thick plywood.

Are sandwich panels as strong as steel or wood?

For the load cases relevant to truck bodies, trailer floors and scaffold planks, thermoplastic sandwich panels match or exceed the structural performance of steel and wood at a lower weight. The key is matching the panel configuration to the specific load requirement: core thickness, skin build-up and panel thickness all influence bending strength and compressive performance.

The strength of a sandwich panel is not a single number. It depends on the combination of core material, core thickness, skin build-up and thickness. A 30 mm panel with a PP honeycomb core and 4-layer glass-fibre skins carries considerably higher loads than a 15 mm wall panel with a lower-density core. Both are sandwich panels, but they serve different structural roles.

For scaffolding, the structural evidence is particularly concrete. A 10.5 mm Compoform panel achieves load class 4 according to EN 12811 without support beneath it — the relevant European standard for scaffold planks under working load. That is a measurable structural benchmark, not a general claim. For truck body floors, a self-supporting 30 mm PP sandwich floor panel eliminates the need for an aluminium subframe, removing a production step and lowering assembly costs for body builders.

Wood, by contrast, varies in strength because it is a natural material. Grain direction, moisture content and knot density all affect performance. Steel is consistent but heavy, and its strength-to-weight ratio is lower than that of a well-specified composite sandwich panel. For applications where the dominant load is bending across a span — such as a trailer floor or a scaffold plank — sandwich panels are a structurally sound alternative to both materials.

What are the durability advantages of sandwich panels over wood?

Thermoplastic sandwich panels last considerably longer than wood in transport and industrial environments. In heavy transport applications, composite panels typically achieve a service life of 12 years or more, compared with 3 to 5 years for plywood under similar conditions. Over a vehicle life of 15 years, that difference eliminates two to three plywood replacement cycles.

Wood degrades through a combination of moisture absorption, delamination, rot and mechanical wear. In a truck body or trailer floor that is regularly washed down, loaded with heavy goods and exposed to fluctuating temperatures, plywood deteriorates relatively quickly. Each replacement cycle brings panel costs, installation labour and vehicle downtime — all factors that raise total cost of ownership in ways that are easy to underestimate when comparing unit prices.

Thermoplastic sandwich panels do not absorb moisture. The glass-fibre-reinforced skins are impermeable, and edge sealing and edge folding protect the core against water ingress at the panel edge — the most vulnerable point in any sandwich construction. This is particularly relevant for scaffold planks and truck body floors that are regularly washed down or exposed outdoors.

The surface finish also contributes to durability. Wall panels with white PET film surfaces achieve more than 22,000 hours of UV resistance, tested according to ISO 4892. Floor panels with black anti-slip surfaces are designed for wear resistance under foot and pallet traffic. Neither finish requires painting, sealing or periodic retreatment — something wood typically needs to maintain its structural and aesthetic properties.

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How do sandwich panels compare with steel in terms of corrosion resistance?

Thermoplastic sandwich panels do not corrode. Steel corrodes once its protective coating is breached — an ongoing maintenance liability in transport and outdoor industrial applications. A composite sandwich panel with glass-fibre-reinforced thermoplastic skins is chemically inert to moisture, road salt, cleaning agents and the range of substances a commercial vehicle body encounters in service.

For truck body builders and trailer manufacturers, corrosion costs are a real operating expense. Steel panels require protective coatings that degrade over time, particularly at cut edges, fastener holes and weld points. Once corrosion sets in, it spreads, and repair work is labour-intensive. A thermoplastic sandwich panel, by contrast, can be cut, drilled and fastened without creating corrosion initiation points, because the material itself is not susceptible to oxidation.

In scaffolding applications, the corrosion argument is equally relevant. Steel scaffold planks and frames exposed to the elements outdoors require regular inspection and treatment to remain safe. Composite scaffold planks eliminate that maintenance burden and retain consistent mechanical properties throughout their service life, without the degradation that rust introduces into the load-bearing capacity of steel.

Are sandwich panels more sustainable than steel and wood?

Thermoplastic sandwich panels offer meaningful sustainability advantages over both steel and wood, primarily through lower lifecycle weight, a longer service life and recyclability at end of life. For European manufacturers subject to CSRD sustainability reporting requirements, the choice of material for structural panels is increasingly a compliance matter and not just a preference.

The weight advantage of sandwich panels has a direct carbon implication in transport. A lighter vehicle body reduces fuel consumption or extends electric range over every kilometre the vehicle drives. Over a vehicle’s service life, the cumulative energy saving from reduced structural mass is substantial, even before taking into account the comparison of production energy between composite and steel manufacturing.

Thermoplastic composites are recyclable. Unlike thermoset composites, which cannot be remelted, thermoplastic panels can be reprocessed at end of life. This is directly relevant to the EU End-of-Life Vehicles (ELV) Directive, which sets recyclability targets for vehicles and their components. Manufacturers who specify thermoplastic sandwich panels for vehicle bodies are choosing a material that supports compliance with those targets.

Wood appears sustainable at first glance, but in heavy transport applications its short service life creates a different kind of environmental cost. Replacing a truck body floor two to three times over a vehicle’s life consumes additional material, generates waste and leads to landfill exposure of treated wood, which has its own disposal implications. A composite panel that lasts the life of the vehicle avoids those replacement cycles entirely.

When should manufacturers choose sandwich panels over traditional materials?

Manufacturers should choose sandwich panels over steel or wood when weight reduction, durability, corrosion resistance or lifecycle cost are the primary decision criteria. In practice, this applies to most commercial vehicle body, scaffold plank and industrial floor and wall panel applications where the operating environment is demanding and replacement costs are significant.

The strongest case for sandwich panels arises when two or more of the following conditions apply:

Payload or range is commercially sensitive — every kilogram saved in the structure adds capacity for revenue-generating cargo or extends EV range per charge
The panel is exposed to moisture, chemicals or outdoor conditions — conditions that degrade wood and corrode steel, but leave thermoplastic composites unaffected
Replacement cycles are costly — when panel costs, installation labour and vehicle downtime make frequent replacement economically painful
Custom dimensions are required — standard steel or wood sheet formats rarely match the exact geometry of a truck body or trailer floor without significant waste or joints
Sustainability reporting applies — CSRD obligations or customer sustainability requirements make material recyclability and lifecycle carbon relevant to purchasing decisions

Steel remains the right choice where extreme point loads, welded attachments or very high compressive loads are the dominant design requirement and weight is not a constraint. Wood may still be suitable for low-cost, short-lived applications where replacement is easy and the operating environment is dry and controlled. Outside those specific conditions, sandwich panels offer a better combination of performance, service life and total cost.

How we help you choose and specify the right sandwich panel

We work with truck body builders, trailer manufacturers and scaffolding companies across Europe to specify sandwich panel configurations that match the requirements of their application precisely. That means we review your load requirements, assembly process and operating environment before recommending a panel — not afterwards.

This is what that looks like in practice:

Application review: We assess your structural load case, the relevant European standard (EN 12811 for scaffolding, trailer floor load specifications for transport) and the environmental conditions the panel will be exposed to in service
Panel configuration: We select the right core material (PP honeycomb or PET foam), core thickness, skin build-up and thickness to meet your performance requirements without over-specifying the panel
Custom dimensions: Panels are available in custom sizes up to 13,500 mm x 2,950 mm, cut to size to your exact specification, so you receive panels that fit your assembly process without modification or waste
Integration support: We flag potential issues before production, whether that concerns edge sealing requirements, fastener compatibility or surface finish selection for your specific application
Lifecycle cost modelling: We help you build the TCO case internally, including the replacement-cycle comparison that easily justifies the composite investment against a lower unit price for plywood or steel

If you are specifying panels for a truck body floor, trailer side wall or scaffold plank and want to understand which configuration suits your load class and assembly process, contact our engineering team directly for panel advice. We review your design, not just your order.