FAQs

How effective is ThermaRoof® as a thermal insulation material?

Extremely effective... essentially because stabilized air is such a good insulator.

The thermal performance of a material is measured in terms of its resistance to the flow of heat. This thermal resistance is expressed in R values, the higher the number, the better the insulation.

50mm thick ThermaRoof® at 28 kg/m3 can give an R value of 1.37 m2K/W.

Does ThermaRoof® 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 ThermaRoof® 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.

ThermaRoof® is said to breathe. What does this mean?

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

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

Does age affect the thermal performance of ThermaRoof®?

No. Depnding on the density RMAX Thermaroof® consists of between 96%-99% air and 4%-1% polystyrene, and nothing else. Because of its cellular structure EPS is dimensionally stable, and will not settle over time. EPS used and installed correctly does not deteriorate with age and as such is able to deliver constant R values for the life of the building.

Is ThermaRoof® strong?

Yes. RMAX Thermaroof® is manufactured in a number of 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.

Is ThermaRoof® 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.

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

In roof construction requiring hot asphalt, care should be taken to follow recommended installation instructions for hot bituminous asphalt to prevent melting or collapse of EPS insulation boards.

Is ThermaRoof® 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 ThermaRoof® 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.

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.

Is ThermaRoof® cost effective compared to alternative insulation?

Because of the high level of versatility of EPS and the wide range of applications for which it is suitable, its cost effectiveness compared to alternative materials can generally be accurately assessed only on a case by case basis.

In many applications however, particularly where an element of structural strength is required, EPS is the most cost effective insulation material available.