How much weight can you save by switching from plywood to sandwich panels?

Compoform · 13 Oct 2026

Switching from plywood to thermoplastic sandwich panels typically saves between 40% and 60% of the panel weight, depending on thickness, core type, and skin configuration. For a truck body or trailer built with wall and floor panels across a large surface area, that reduction can translate into hundreds of kilograms of structural dead weight eliminated. The sections below work through the numbers, the structural trade-offs, and the commercial case for making the switch.

How much lighter are sandwich panels compared to plywood?

A thermoplastic sandwich panel is typically 40% to 60% lighter than plywood of comparable thickness and structural performance. Standard plywood used in truck bodies and trailer floors commonly weighs between 6,000 and 9,000 g/m² depending on thickness, while a thermoplastic sandwich wall panel can weigh as little as 2,763 g/m² at 17 mm, based on Compoform’s own technical data.

To put that in concrete terms, a 17 mm wall panel with a PP-foam core and 2-ply glass-fibre skins on both faces weighs approximately 2.8 kg per square metre. A 20 mm cross-ply wall panel comes in at around 2.9 kg/m². Even the heavier floor panel variants, which use a denser PP-honeycomb core to handle higher compressive loads, weigh 5.5 to 7.6 kg/m² at 15 to 30 mm thickness. Structural plywood at equivalent thicknesses typically exceeds those figures significantly.

The weight advantage is not uniform across every panel type. Floor panels carry more load and therefore use denser cores, which adds weight relative to wall panels. But even the heaviest floor panel in the range remains competitive with plywood on a weight-per-unit-of-structural-performance basis, not just on raw areal weight.

What factors determine how much weight you actually save?

The actual weight saving depends on four main variables: panel thickness, core material and density, skin configuration, and the total surface area being replaced. Changing any one of these factors shifts the outcome significantly, which is why the weight saving on a trailer sidewall will differ from the saving on a cargo box floor panel application.

Core type and density

PP-foam cores are available in densities from 40 to 140 kg/m³. Lower-density foam cores produce lighter panels suited to wall cladding and non-structural applications. Higher-density PP-honeycomb cores, used in floor panels, are heavier but deliver the compressive strength needed to support vehicle loads and foot traffic. Choosing the right core for the application avoids over-engineering, which is one of the most common sources of unnecessary weight in panel specifications.

Skin architecture and ply count

A 2-ply glass-fibre skin weighs around 925 g/m² per face. A 4-ply skin weighs approximately 1,625 g/m² per face. The difference matters when you are specifying panels across a large surface area. An asymmetric panel with a 2-ply skin on one face and a 4-ply skin on the other, such as the 17 mm 2P/4P variant, weighs 3,638 g/m², noticeably more than the symmetric 2-ply version at 2,763 g/m². Matching the skin specification to the actual load direction avoids adding weight where it is not needed.

How does weight reduction translate into payload or revenue gains?

Every kilogram saved in body structure is a kilogram that can be converted into legal payload capacity. For a truck or trailer operating at or near the legal gross vehicle weight limit, reducing structural weight directly increases the revenue-generating cargo the vehicle can carry on every run. Over a full year of operation, that additional payload capacity compounds into meaningful revenue.

Consider a trailer body where switching from plywood to sandwich panels saves 300 kg of structural weight across walls, ceiling, and floor. At a typical freight rate, that additional payload capacity generates additional revenue on every loaded trip. The weight saving does not require any change to the vehicle’s powertrain, tyres, or axle configuration; it is a structural decision with a direct commercial outcome.

In 2026, weight reduction carries a second argument that procurement teams at EV fleet operators are raising directly with their body builders: battery range. Lighter body structures extend the range of electric trucks and vans on a single charge. Every kilogram of structural dead weight reduces range per charge, which affects route planning, charging infrastructure requirements, and total operating cost. For EV fleet buyers, weight reduction is a range argument as much as a payload argument, and it is becoming a standard specification requirement in procurement conversations.

Are sandwich panels structurally strong enough to replace plywood?

Yes. Thermoplastic sandwich panels are structurally capable of replacing plywood in wall, floor, and structural applications, provided the panel specification is matched to the load requirements. The sandwich construction, stiff skins bonded to a lightweight core, delivers high bending stiffness relative to weight, which is the same structural principle that makes plywood effective, but achieved at a fraction of the mass.

For floor applications, PP-honeycomb cores with 4-ply glass-fibre skins handle the compressive and bending loads typical of truck and trailer floors. A 30 mm floor panel sustains an average maximum load of 5,647 N in standardised testing (Compoform test data, January 2023), while the 15 mm variant sustains 3,240 N. These are not laboratory curiosities; they are the basis for specifying panels into production vehicles.

For scaffolding applications, an 11 mm Compoform panel has achieved EN 12811 load class 4 with no support underneath. EN 12811 is the European standard for temporary works equipment, and load class 4 represents a demanding service load. That result demonstrates that sandwich panels are not just a lightweight alternative to plywood; they are a structurally verified one.

One practical advantage worth noting: a 30 mm PP sandwich panel floor is self-supporting and requires no aluminium subframe. For truck body builders, this removes a production step and reduces both material cost and assembly time, a structural benefit that also simplifies the build process.

What other benefits come with switching beyond weight savings?

Weight saving is the most immediate benefit, but it is not the only one. Thermoplastic sandwich panels outperform plywood on lifespan, maintenance, moisture resistance, and end-of-life recyclability, all of which affect the total cost of ownership over a vehicle’s working life.

Longer service life: Thermoplastic panels last 12 or more years in heavy transport applications, compared to 3 to 5 years for plywood. Over a 15-year vehicle life, a composite floor eliminates two to three plywood replacement cycles. Once you factor in panel cost, installation labour, and vehicle downtime for each replacement, the composite floor is cheaper per year of service even at a higher unit price.
Moisture and chemical resistance: Plywood absorbs moisture, swells, and degrades when exposed to repeated washing, spills, or outdoor conditions. Thermoplastic panels do not absorb water. Edge sealing and edge bending protect the core from UV exposure and moisture ingress, which is particularly relevant for scaffolding boards and truck floors that are washed down regularly.
Consistent dimensions: Plywood is a natural material with inherent variability. Thermoplastic sandwich panels are manufactured to precise tolerances, which simplifies assembly and reduces fitting time on the production line.
Recyclability and regulatory compliance: Thermoplastic panels are recyclable at end of life. For European OEMs, this is increasingly a compliance requirement under the EU End-of-Life Vehicles (ELV) Directive and CSRD sustainability reporting obligations, not just a preference. Specifying recyclable materials now reduces compliance risk as these regulations tighten.
Surface finish options: Wall panels are available with a white PET-film surface finish that provides over 22,000 hours of UV resistance and a finished decorative surface requiring no additional treatment. Floor panels carry a black anti-skid surface inherent to the product. Neither requires painting or sealing after installation.

How Compoform Helps You Switch from Plywood to Sandwich Panels

We work with truck body builders, trailer manufacturers, and other European OEMs to specify the right panel configuration for their application, not the heaviest panel that will pass a load test, and not the lightest panel that might fail in service. The difference between those two outcomes is an engineering conversation, and that is where we start.

Here is what that looks like in practice:

Application review: We review your current design, load requirements, and assembly process before recommending a panel specification. If your floor is currently 18 mm plywood, we identify which sandwich panel configuration matches or exceeds that structural performance at lower weight.
Custom dimensions: Panels are available in custom dimensions cut to your exact specification, up to 13,500 mm × 2,950 mm. If your current plywood comes in standard sheet sizes that require on-site cutting and joining, we can supply panels that fit your body dimensions directly.
Core and skin optimisation: We match core density and skin ply count to the actual load direction and service conditions of your application. Wall panels, floor panels, and structural panels each have different requirements, and over-specifying adds weight and cost without adding performance.
Post-sales support: We support you through integration, any issues that arise in production, and iteration as your design evolves. We are not a supplier that ships panels to a purchase order and moves on.

If you are evaluating a switch from plywood to sandwich panels for a truck body, trailer, or cargo box application, bring us your current specification. We will review it, identify where the weight and cost savings are, and flag any integration considerations before you commit to a production change. Contact our team to discuss your specification.