Sandwich panels (sometimes referred to as composite panels or structural insulating panels (SIP)) consist of two layers of a rigid material bonded to either side of a lightweight core. The three components act together as a composite; that is, the combination of the characteristics of the components results in better performance than would be possible if they were acting alone.

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The lightweight core keeps the two faces in the correct position, resists shear forces, and provides insulation, while the two faces provide durability, weather and impact resistance, and resist in-plane forces of tension and compression.

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Sandwich panel systems include the panels themselves, the joints between them, fixings (often concealed) and a support system.

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Uses

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Sandwich panels are widely used as an external cladding for single and multi-storey buildings, where they are required to provide weather resistance, and resistance to wind-loading, access loads, self-weight and so on. However, they are also used to create insulated internal envelopes, ceiling panels, partitions (for example in cold stores) and for fire-resisting compartment walls.

Building types that commonly feature sandwich panels include:

• Industrial buildings and processing plants.

• Temporary buildings.

• Storage buildings.

• Clean rooms.

• Agricultural buildings.

• Shopping centres.

• Sports facilities.

• Transport buildings.

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Materials

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The outer faces of sandwich panels are most commonly made of metals such as:

• Hot-dip galvanized steel sheet.

• Aluminium.

• Zinc.

 

However, other materials that can be used include:

• Preecast concrete, sometimes clad with other finishes such as brick.

• Cement board.

• Glass fibre reinforced polypropylene.

• Poly vinyl chloride (PVC).

• Magnesium oxide board (MgO).

• Plywood.

• Oriented strand board (OSB).

• Glass reinforced plastic (GRP).

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Cladding systems typically include a rigid polyurethane core, but other core materials include:

• Expanded polystyrene (EPS).

• Extruded polystyrene (XPS).

• Mineral wool (rock fibre) (MWRF).

• Modified Phenolic foam (MPHEN).

• Polyisocyanurate (PIR).

• Honeycomb materials (such as Polypropylene).

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Properties

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Sandwich panels can be selected because of their:

• Ease and speed of installation.

• Rigidity.

• Thermal, fire and sound insulation.

• Airtightness

• Robustness and durability

• Low maintenance / cleaning requirements.

• Low capital cost.

• Low lifetime costs

• Chemical and biological resistance

• Light weight.

• Weather resistance.

• Dimensional stability.

• Availability as standard products off-the-shelf.