Expanded polystyrene is a lightweight, rigid plastic foam insulation material produced from solid beads of polystyrene. Expansion is achieved by virtue of small amounts of pentane gas dissolved into the polystyrene base material during production. The gas expands under the action of heat, applied as steam, to form perfectly closed cells of expanded polystyrene. These cells occupy approximately 40 times the volume of the original polystyrene bead. The expanded polystyrene beads are then moulded into approximate forms suited to their application.

Anyone who needs to thermally insulate walls, roofs or floors will find expanded polystyrene the ideal, cost effective and easy to use material in all types of building, from houses and offices to factories and schools. Expanded polystyrene is used by civil engineering as a lightweight fill or void – forming material. It is also used as floatation material.

For today’s building and construction industry, concerns are being addressed by the careful choice of building materials, and in particular, the selection of insulation. Expanded polystyrene can contribute towards a better environment in this field.


  • Excellent thermal insulation – Expanded polystyrene is 98% air, and is therefore an excellent thermal insulant.
  • Moisture resistant – Expanded polystyrene resists degration by water.
  • Lifetime durability – Expanded polystyrene does not decompose. It therefore provides lifetime durability.
  • Flexible mechanical properties – With its flexible production process, the mechanical properties of expanded polystyrene can be adjusted to suit every specified application.
  • Versatile – Expanded polystyrene can be manufactured into almost any shape or size and is compatible with a wide variety of materials.
  • Cost effective – Expanded polystyrene offers the best price/performance ratio compared to any other insulation material.
  • Easy to transport – Expanded polystyrene is almost as light as air, so it saves fuel in transport.
  • Easy to install – Expanded polystyrene is light, practical, safe and easy to handle and install.
  • Fire retardant – In addition to standard expanded polystyrene there is also a “self extinguishing” version that includes a fire retardant.

The Expanded polystyrene cornices we supply at Polystyrene Xstreme is a lower density but substantially cheaper than the XPS cornices.

  • Cornices are used to hide the small openings usually present where the wall and the ceiling meet. Cornices can also add ambiance to a room and will give a room character, depending on the style of cornice chosen.
  • Expanded polystyrene cornices are resistant to humidity and water making them an excellent choice for humid areas.
  • Expanded polystyrene cornices are lightweight and easy to install.


All polystyrene products can be painted with acrylic or PVA based paints.