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 several closed hollow cells in each particle.

EPS particle are closed cell and cannot absorb water. During the process of molding 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 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.

No, EPS does not have a capillary action. EPS is ideally suited when the insulation material is in contact with the ground.

The breathability characteristic of EPS refers to its ability to allow any absorbed moisture to escape when condition change. It therefore reduces any tendency towards the formation of vapor dams.

In applications where high humidity and temperature differentials are likely, a water vapor barrier such as plastic sheeting should be used. The vapor barrier is best installed on the warm side of the structural component, with the warm side of the structural component, with the insulation as near as possible to the cold side.

Yes. EPS is manufactured in several classes (or densities), and each class exhibits excellent compressive and flexural strength and dimensional stability characteristics at a very high strength to weight ratio.

The range of classes available enables specifiers to select the most appropriate balance between structural and insulation properties for any building application.

It depends. It is resistant to virtually all aqueous media including dilute acids and alkalis and to methanol, ethanol and silicone oils. See the table of chemicals resistance int his brochure.

It has limited resistance to paraffin oil, vegetable oils, diesel fuel and Vaseline, which may attack the surface of EPS after long-term contact.

It is not resistant to hydrocarbons, ketones, esters, paints containing thinners, and solutions of synthetic adhesives.

Prolonged exposure to sunlight will cause a slight discoloration (yellowing) of PES insulation and cause some surface embrittlement.

Even so, the thermal insulation properties will not be affected unless exposure results in loss of thickness of the EPS boards, although the friable surface can make bonding difficult. For this reason, EPS insulation should be covered to protect it from UV light if it is to be stored in the open for extended periods.

Yes, because EPS is an inert, organic material, it will not rot and is highly resistance to mildew. It also provides no nutritional value to ants, termites and rodents.

To prevent damage to EPS by pests and insects seeking to gain access to the other materials in buildings which provide a food source, EPS may be coated with a thin cement slurry.

Provided EPS does not suffer mechanical damage or failure of any fittings that may be used, it should have a life equal to that of the building in which it is installed.

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.

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 chlorine.

In almost any application where insulation or a combination of insulation and strength are required.

As an insulation material, it is used in a number of roof, wall, ceiling, and sub floor systems… often in combination with other materials such as steel (in sandwich panels commonly used for cold store construction), concrete (as an insulation core in tilt up wall panels) and gypsum and plasterboard (as skins for ceiling panels and other prefabricated components).

Yes. Manufacturers when stating the class of EPS and therefore its physical characteristics are required to manufacture to AS 1366, 3, 1992. As such, he properties of EPS required for a application are guaranteed. Where the densities exceed the AS1366 – 3 – 1992 grade levels Queensland Polystyrene Specialists has measured the properties and provides specification sheets for these high-density grades.