
VOID FORMERS
Polystyrene is uniquely suited to the construction industry due to its insulation properties, compressive strength, and low density. Specific applications include underfloor void formers and wall cavities, reducing insulation requirements and saving costs on other expensive materials, such as concrete.
Insulation properties and compressive strength are a factor of:
Density

Polystyrene density determines compressive thresholds (affecting the force it can withstand) and R-values (an indicator of its insulative properties). Higher density results in higher R-values.
Thickness

Polystyrene blocks can be cut to various thicknesses, generally ranging from 10mm to 200mm depending on the use case. Thicker polystyrene provides greater insulation than thin sheets of polystyrene.
Profile

Polystyrene can be cut into various profiles for each application, including rib-and-block. Cumulus has an advanced automated cutting line, as well as CNC-cutting machines to cater for any need.
HEAT TRANSFER CALCULATIONS
Thickness (mm)
Density (kg/m³)
Thermal Cond. (W/m.K)
Thermal Trans. U (W/m².K)
Thermal Resist. R (m².K/W)
Temp. diff. (⁰C)
Heat Transfer (W/m²)
50
15
0.038
0.760
1.32
15
11.40
125
15
0.038
0.304
3.29
15
4.56
Thickness (mm)
Density (kg/m³)
Thermal Cond. (W/m.K)
Thermal Trans. U (W/m².K)
Thermal Resist. R (m².K/W)
Temp. diff. (⁰C)
Heat Transfer (W/m²)
50
20
0.035
0.700
1.43
15
10.50
125
20
0.035
0.280
3.57
15
4.20

