GRP Sandwich Panels For Structural & Cladding Applications
18mm GRP sandwich panels combine fibreglass-reinforced outer skins with a lightweight foam core to create a rigid composite panel with excellent strength-to-weight characteristics. The construction provides high levels of durability, thermal insulation and moisture resistance while maintaining a significantly lower weight than many traditional construction materials.
The panels are commonly used for industrial enclosures, access structures, vehicle bodies, flooring systems, wall cladding, service housings and infrastructure projects where weight reduction and long-term performance are important design considerations.
Available with a range of core materials, surface finishes and colour options, panels can be manufactured to project-specific requirements.
18mm GRP Sandwich Panel Performance Characteristics
| Characteristic | Description |
|---|---|
| Construction | GRP skins bonded to a rigid foam core |
| Core Options | PU, XPS and PVC foam cores |
| Weight | Lightweight composite construction |
| Thermal Performance | Provides thermal insulation and dimensional stability |
| Moisture Resistance | Suitable for humid and external environments |
| Surface Finishes | Smooth, gritted, coloured and textured finishes |
| Colours | Standard and project-specific colours available |
| Fire Performance | Fire-retardant options available |
| Fabrication | Panels can be cut and manufactured to project requirements |
| Typical Applications | Cladding, flooring, enclosures and structural panels |
Technical Information
- Lightweight – Easier to transport, handle, and install compared to traditional materials
- High strength-to-weight ratio – Offers excellent structural performance without excessive weight
- Waterproof and moisture-resistant – Ideal for humid, wet, or damp environments
- Chemical and corrosion resistant – Withstands exposure to harsh chemicals and cleaning agents
- Thermally insulative – Core material provides good insulation, improving energy efficiency
- Durable and impact-resistant – Long-lasting even in heavy-use or high-traffic areas
- Hygienic surface – Smooth GRP skins are easy to clean and inhibit bacteria or mould growth
- Low maintenance – Requires minimal upkeep over its lifespan
- Fire retardant options available – Panels can be made to comply with specific fire safety standards
- Customisable – Available in different colours, finishes, and core densities to suit specific needs
| Property | Typical Value/Range |
|---|---|
| Overall Thickness | 18mm |
| GRP Skin Thickness | 1.0mm–2.0mm each side |
| Core Material | PU foam, XPS foam, or PVC foam |
| Thermal Conductivity (U-value) | ~0.8–1.2 W/m²K (depends on core) |
| Compressive Strength | 150–300 kPa (varies with core material) |
| Flexural Strength | 60–120 MPa (depending on core and GRP quality) |
| Panel Weight | 2.5–5.0 kg/m² |
| Fire Rating | Class 1 or Class 0 (if fire-retardant resin is used) |
| Water Absorption | <0.5% |
| Standard Panel Size | 2440mm x 1220mm or custom sizes |
Typical Applications Of 18mm GRP Sandwich Panels
18mm GRP sandwich panels are commonly used within industrial buildings, service enclosures, access structures, transport infrastructure, vehicle bodies, plant rooms and modular construction projects. Their combination of low weight, rigidity and moisture resistance makes them suitable for applications where traditional timber, steel or solid GRP panels may be less practical.
Panels can also be manufactured with project-specific surface finishes, colours and core materials to suit environmental, structural and thermal performance requirements.
Weight Reduction & Structural Performance
The sandwich panel construction combines two GRP outer skins with a lightweight core to create a panel with excellent rigidity while minimising overall weight.
This makes sandwich panels particularly suitable for vehicle bodies, enclosures, modular structures and access systems where strength, dimensional stability and reduced handling weight are important considerations.
18mm GRP Sandwich Panel FAQs
An 18mm GRP sandwich panel is a composite panel made from two fibreglass-reinforced plastic skins bonded to a rigid foam core. This construction delivers a lightweight but strong panel that can be used for structural, cladding and enclosure applications.
Despite their low weight, 18mm GRP sandwich panels offer a high strength-to-weight ratio. The combination of GRP skins and rigid core provides good compressive and flexural strength, making them suitable for many industrial, commercial and public access projects.
Yes. The GRP skins are waterproof and the core is moisture-resistant, making the panels ideal for humid, wet or damp environments such as plant rooms, wash-down areas and coastal locations.
Yes. The smooth GRP surface is easy to clean and helps inhibit bacteria or mould growth. This makes 18mm GRP sandwich panels a good choice for hygienic environments, food processing facilities and wash-down spaces when combined with appropriate cleaning regimes.
Where required, panels can be manufactured using fire-retardant resin systems to achieve Class 1 or Class 0 ratings in line with relevant BS and EN standards. We can advise on the best build-up to meet your fire performance requirements.
Yes. Panels can be cut, shaped and edge-detailed to suit openings, penetrations and project-specific layouts. We can also provide pre-fabricated sections with embedded or surface-mounted fixings so they are ready to install on site.
Standard panels are typically supplied at 2440 mm x 1220 mm, with other sizes available by request. Black is the standard colour, but other colours and finishes can be specified to suit your project or branding.
Absolutely. If you share your loading, environmental and fire performance requirements, we can recommend the most suitable core type, skin thickness, resin system and fixings for your 18mm GRP sandwich panels.
Need Technical Advice or a Quote?
Advice is available on panel selection, loading requirements, span capability, fabrication options and installation methods. Drawings, specifications and project information can be reviewed to assist with product selection and system design.