TECHNICAL DATA 
Delta Insulation Systems 
P: +61 07 3271 2170   E: info@deltainsulationsystems.com   W: www.deltainsulationsystems.com.au 
A: 49 Bernoulli Street, Darra Qld. 4076   ABN: 12 122 760 552 
Page 3 of 4 
 
 
 
Thermal Properties  
  
EPS gains its exceptional insulating properties from 
the stabilised air trapped within its cellular structure. 
Since it contains no CFCs or any other gas that may 
leak out, it will not harm the ozone layer or decrease 
its insulation properties.  
  
As Australian Standard 1366 Part 3 is a minimum 
conformance standard the thermal resistances quoted 
will be achieved as a minimum in 97.5% of cases in a 
statistical sample, when tested at a mean sample 
temperature of 25°C.  
  
For design purposes the average thermal resistance 
is a better guide than the minimum thermal resistance 
(refer table 3).  
  
  
Moisture Resistance  
  
Of all the materials used for insulation applications, 
EPS is one of the most resistant to the adverse 
effects of moisture content.  At ten times its dry 
weight, EPS has been found to maintain 80% of its R 
value.  
  
  
Floatation Properties  
  
The density of EPS is low compared to water, with a 
normal density range of 11 to 32 kg/m3 compared to 
water at 100 kg/m3. The water buoyancy per cubic 
metre of EPS is determined by subtracting its kg/m3 
density from 1000. The result is the weight in 
kilograms that a cubic metre of EPS can support 
when fully submerged in water.  
  
  
Temperature Cycling  
  
EPS is able to withstand the effects of temperature 
cycling thereby providing long term performance in 
low temperature applications.  
 
 
 
 
Core specimens of EPS removed from freezer walls in 
place for twenty years have demonstrated no 
deterioration in the structural integrity or physical 
properties.  
  
The K Value of EPS decreases at lower average mean 
temperatures, hence its popularity and success in 
subzero applications.  
  
  
Toxicity  
  
Extensive research programs have been conducted 
overseas (i) to determine if thermal decomposition 
products of EPS present a toxicity hazard. The test 
results have revealed that these decomposition 
products are less harmful than those of burning wood.  
  
Gases released during combustion are predominantly 
carbon monoxide and, to a lesser extent, carbon 
dioxide. A CSIRO report (ii)comments that the toxicity of 
the gases associated with the burning of EPS is no 
greater than that associated with timber.  
  
  
Combustibility  
  
As with all other organic material, EPS insulation 
products must be considered combustible and to 
constitute a fire hazard if improperly used or installed.  
  
EPS products should not be exposed to open flames or 
other ignition sources.  
  
The material contains a flame retardant additive to 
inhibit accidental ignition from small fire sources. Table 
2 shows test results for ES and other common building 
materials to provide a good guide as to how these 
products compare.  
  
(i) H.Hoffmann & H Oettel “Comparative Toxicity of 
Thermal Decomposition Products  
  
(ii) P.R.Nicholl & K.G. Martin “Toxicity Considerations of 
Combustion Products from Cellular Plastics.”  
Table 2  
Comparative testing of some materials to AS 1530, Part 3 – Early Fire Hazard Test  
Material  
Ignitability Index  
(0-20)  
Spread of Flame  
Index  
(0-10)  
Heat Evolved Index  
(0-10)  
Smoke developed 
index  
(0-10)  
EPS  
12  
0  
3  
5  
Australian Softboard  
16  
9  
7  
3  
Oregon  
13  
6  
5  
3  
Bluegum  
11  
0  
3  
2  
Source: EBS Notes on the Science of Building NSB66 

View this content as a flipbook by clicking here.