Technical Information


Foam Technologies EPS Block is manufactured to AS 1366, Part 3-1992, Rigid Cellular Plastic Sheets for Thermal Insulation, Rigid Cellular Polystyrene, in six classes. The standard designates a colour to identify each of the six classes:

Class L: Blue Class M: Black

Class SL: Yellow Class H: Green

Class S: Brown Class VH: Red

The standard specifies the minimum physical property limits for each of the six classes (See

Table 1) and methods for determination of compliance

The thermal conductivity of expanded polystyrene sheet grades is shown in the reference below.

SL Grade k = 0.041 W/mk*
S Grade k = 0.0397 W/mk*
M Grade k = 0.0383 W/mk*
H Grade k = 0.0368 W/mk*
VH Grade k = 0.0352 W/mk*
* k value @ reference temperature 25°C

Nominal R-values (m²K/W) – excluding surface resistance

EPS sheet thickness SLGrade SGrade MGrade HGrade
41mm 1.00 1.05 1.07 1.11
50mm 1.25 1.32 1.33 1.39
75mm 1.90 1.97 2.00 2.08
100mm 2.50 2.63 2.67 2.78

Standard Sheet Sizes

Our standard size sheets below can be ordered in varying thicknesses from 10mm to 600mm.

2400mm x 1200mm

3600mm x 1200mm

Non-standard sized sheets and varying thicknesses are readily available and cut to your specific order requirements.