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What exactly is Expanded Polystyrene (EPS)?

It is a lightweight cellular material consisting of fine spherical shaped particles, which are comprised of 96% - 99% air and 4% - 1% polystyrene. This air is trapped within a number of closed hollow cells in each particle.

How is RMAX GeoFoam® manufactured?

When raw EPS particles 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.

Blocks of EPS are made by resoftening the expanded particles in a block mould with steam until they fuse together. The block is then cut into sheets or boards.

Shaped EPS products are produced either by cutting blocks with a hot wire or by direct moulding of the expanded particles in specially shaped moulds.

Does RMAX GeoFoam® absorb water?

EPS is a closed cell and does not readily or significantly absorb water. During the process of moulding a block of EPS, tiny channels are formed between the EPS particles. If the material is immersed in water these tiny channels can be filled with water. Testing has shown that after immersion for more than 360 days, there may be only 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 marine applications such as floating pontoons, bouys, fishing floats and other applications, which involve full or partial submergence in water for prolonged periods of time.

Does RMAX GeoFoam® have a capillary action?

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

Is RMAX GeoFoam® strong?

Yes. EPS is manufactured in a number of classes (or densities), and each class exhibits excellent compressive and flexural strength and dimensional stability characteristics 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.

Is RMAX GeoFoam® resistant to chemicals?

It depends. It is resistant to virtually all aqueous media including dilute acids and alkalis and to methanol, ethanol and silicone oils.

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

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

In road construction, where the EPS is placed under the road surface care should be taken to protect the EPS by covering and sealing with an impermeable membrane to prevent petrol, hot bituminous asphalt or solvent spills reaching the EPS.

Is RMAX GeoFoam® degraded by ultraviolet light?

Prolonged exposure to sunlight will cause a slight discolouration (yellowing) of EPS 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.

Is RMAX GeoFoam® durable?

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

Does RMAX GeoFoam® contain CFCs?

No. EPS is chlorofluorocarbon (CFC) and hydro chlorofluorocarbon (HCFC) free.

At no stage during the manufacture or application of EPS is the use of CFCs or HCFCs, or other compounds that are thought to contribute to the destruction of the earth's ozone layer, required.

Is RMAX GeoFoam® subject to Australian Standards?

Yes. Where manufacturers of EPS are declaring the class of EPS in accordance with AS 1366 Part 3 - 1992 they are required to meet the physical requirements of that particular class and also state the class on the product. RMAX is the only EPS producer in Australia to have a National Association of Testing Authorities Australia (NATA) accredited laboratory that routinely tests and confirms RMAX GeoFoam® EPS is meeting the requirements of AS 1366 Part 3 - 1992.