What exactly is Expanded Polystyrene (EPS)?
It is a lightweight cellular material consisting of fine spherical shaped particles which are comprised of 98% air and 2% polystyrene. This air is trapped within a number of closed hollow cells in each particle.
How is EPS manufactured?
When raw EPS beads containing a blowing or expanding agent are softened by heating with steam, the hollowed closed cells are formed within the particles which expand to up to 50 times their original volume to form a cellular foam structure.
Does EPS absorb water?
EPS is a closed cell and cannot absorb water. During the process of moulding a block, tiny channels are formed between the EPS particles. If the material is immersed in water these tiny channels can be filled with water. After immersion for more than 360 days, there may be up to 6% water content by volume which has entered the channels.

Even under such an adverse and rare condition of prolonged saturation, EPS suffers little adverse effect. It maintains its shape, size, structure, cohesion and physical appearance. The ability of EPS to resist the adverse effects of moisture is exemplified by its widespread use in floats, marinas and other applications, which involve full or partial submergence in water for prolonged periods of time.

Does EPS burn?
Because EPS insulation boards contain a fire retardant additive, they do not present an undue fire hazard when correctly installed.

Like timber, particle board and other organic building materials, EPS will burn when in contact with a flame. Due to the presence of the fire retardant additive in EPS, this flame will self-extinguish almost immediately after the fire source is removed.

Does EPS give off toxic fumes?
The level of toxicity of EPS in a fire situation is no greater than that of timber and other commonly used building materials; the same toxic gas, carbon monoxide is produced. Also produced are carbon dioxide and soot (carbon). There is no emission of such gases as hydrogen cyanide or hydrogen chloride.
Is EPS subject to Australian Standards?
Its physical properties are manufactured to comply to AS 1366 Part 3 – 1992.
Is EPS cost effective compared to alternative insulation?
In many applications where an element of structural strength is required, EPS is the most cost effective insulation material available.

EPS is the only insulation material that in practical, economic and efficiency terms, can be applied to all areas of building constructions – ceilings, roofs, walls, floors and under slab – to provide superior standards of thermal insulation. That’s why EPS is the ultimate insulation.

Environmental aspects

EPS foam supplied by Foam Technologies contains no hydro fluorocarbon (HFC) or hydro chlorofluorocarbon (HCFC) blowing agents that might cause ozone depletion.

When used as insulation and cladding EPS provides a reduction in energy use and costs for cooling in summer or heating in winter. EPS is carbon negative – saving much more in energy than was used to make the raw material.

  1. Modern building practices now require new construction to conform to six star energy ratings putting pressure on architects and builders to explore new and efficient materials that will assist in achieving this.
  2. Efficient insulation will keep a building cool in summer by reflecting heat and warm in winter by retaining heat. This not only makes the structure more comfortable all year round but will save money on reduced heating and cooling costs. Over the life of a building, efficient insulation will more than pay for itself.
  3. The insulation performance lasts the life of the structure and does not deteriorate. It continues to reduce building energy requirements and emissions long into the future.