Marble lightweighting: how sandwich panels make stone lighter

Lightweighting marble and natural stone has become a central topic in many contemporary architecture, design and contract projects. The evolution of formats, the increase in vertical applications and the demand for increasingly large and lightweight surfaces require a technical rethinking of how natural stone is used, without compromising its aesthetic value.
In this context, sandwich panels represent a well-established and reliable solution for transforming marble into a lighter, more stable and safer material, significantly expanding its application potential.

Why lightweight marble

Solid marble, although a noble and durable material, has inherent limitations related to weight and handling during installation. In sectors where lightness is a strict technical requirement—such as aerospace, marine, elevators and transportation—the use of traditional solid stone is often incompatible with structural and design constraints
Even in construction and architecture, with the growing use of large slabs and vertical applications, handling, installation and structural verification become increasingly complex as panel size increases, particularly for façades and continuous cladding systems.
Lightweighting significantly reduces the overall weight of the finished panel, improving safety during installation, simplifying handling and making natural stone compatible with modern construction systems and new design requirements, without sacrificing the original material’s aesthetic appeal.

What lightweight marble is

Lightweight marble is a technical solution that enables a more efficient use of natural stone by bonding a reduced-thickness stone slab to a lightweight structural backing. This approach preserves the aesthetic appearance and surface quality of marble while improving its mechanical behaviour and substantially reducing the overall weight of the panel.
The use of sandwich panels as a technical backing results in a stable, load-sharing structure in which natural stone is no longer an isolated element, but an integral part of a composite system designed to meet specific application requirements.

Sandwich panels for marble lightweighting

Marble lightweighting relies on sandwich panels developed for structural and semi-structural applications, capable of providing stiffness, dimensional stability and long-term reliability. Within this framework, the STEP series , has been specifically designed to work in synergy with natural stone.
These panels combine lightweight cores—such as aluminium honeycomb, aramid paper or polymer-based materials—with fibreglass skins impregnated with epoxy or phenolic resins. The resulting sandwich structure distributes stresses, limits deformation and improves the safety of the finished panel, even in large-format applications.

The splitting technique applied to marble

Among the most advanced solutions for natural stone lightweighting is the splitting technique, which allows two usable stone surfaces to be obtained from a single slab. This process optimises the use of natural material while reducing the weight of the final panels.

In the splitting process, sandwich panels are bonded to both sides of the marble slab prior to separation. During this phase, the sandwich structure absorbs and redistributes internal stresses within the stone, enabling controlled separation and reducing the risk of uncontrolled cracking. The result is two lightweight marble panels, each supported by a stable and high-performance technical structure.

The role of sandwich panels in splitting

The success of the splitting process largely depends on the behaviour of the technical backing. Sandwich panels specifically designed for this application play a crucial role in stress compensation and slab stabilisation during and after separation.
Thanks to the combination of lightweight core and skins, the sandwich panel works collaboratively with the natural stone, limiting the propagation of microcracks and improving the reliability of the finished panel. This approach enables the splitting technique to be applied even to large-format slabs or particularly delicate stone materials

Compocel AL and selected applications

Alongside panels specifically developed for marble lightweighting, Compocel AL can also be used as a technical backing in selected applications. Thanks to its aluminium honeycomb core and aluminium skins, Compocel AL offers high flatness and geometric precision—features appreciated in contexts where dimensional control is a key requirement.
Its use in lightweight marble applications is generally limited to specific cases, but it represents an effective solution when design requirements demand tight tolerances and exceptionally regular surfaces.

Lightweight marble and backlighting

Marble lightweighting also opens up new possibilities in the field of backlighting, increasingly used in architecture and interior design. Reducing stone thickness, combined with an appropriate technical backing, makes it possible to integrate lighting systems behind the panel and achieve controlled luminous surfaces.
In these applications, the sandwich panel contributes not only to mechanical strength, but also to long-term system stability and proper light diffusion, becoming an integral part of the project rather than a simple support.

Applications of lightweight marble

The use of sandwich panels for marble lightweighting is found in numerous sectors where weight, performance and durability are critical factors. These include architecture, interior design, contract projects, the marine sector and, more broadly, all applications in which natural stone must be integrated into complex technical systems.
In these contexts, lightweight marble makes it possible to combine the aesthetic value of natural stone with the demands of contemporary design and engineering.