NBS Source


Biologically inert, Eraboard insulation boards do not emit gases or toxic substances, and do not allow static electricity to build up. Eraboard's main constituent is perlite, a naturally occurring volcanic stone found in surface beds that is so environmentally safe it is even used to filter drinking water. Through a high-tech manufacturing process, perlite is ground into granules, expanded and then mixed with cellulose fibres, glass fibres, binders and special additives. The resulting conglomerate is formed into sheets of varying thickness which are cut into boards with constant dimensions. The range also includes the Eraboard S version, whose upper face is coated with blown bitumen and covered with burn-off film to ensure that torch applied bitumen-polymer membranes are easier to bond to the board and adhere more effectively.


  • Density: 150 kg/m³.
  • Water vapour diffusion resistance factor: 5 μ.
  • Thermal conductivity: 0.050 W/mk.
  • Compressive strength at 10% deflection: 300 kPa.
  • Compressibility class – UEAtc: Class D.
  • Compressibility class – IGLAE: Class E.
  • Shear strength (one-piece boards): 40 kPa.
  • Flexural strength (ASTM C 203/58 – lengthwise): ≥500 kPa.
  • Water absorption by total immersion: ≤0.03 kg/dm³.
  • Dimensional stability at 23°C and 90% RH: ≤0.5–1%.
  • Permanent set after stabilization at 80°C (UEAtc): ≤1.2 mm/m.
  • Reaction to fire: Class 1.
  • Euroclass 13501-1: C, s1, d0.


Complies with BS EN 13169.

General information

Uniclass 2015

Pr_25_57_51_74 Rubber studded sheetsPrimary


J41/10 Built-up reinforced bitumen membrane warm deck roof covering

J41/110 Built-up reinforced bitumen membrane warm deck roof covering

J41/115 Single layer reinforced bitumen membrane warm deck roof covering

J41/430 Warm deck roof insulation

Specification data - Rubber studded sheets

Product Reference


Eraboard S

Blown bitumen coated upper face.


600 mm


1000 mm


20 mm

25 mm

30 mm

35 mm

40 mm

45 mm

50 mm

60 mm

70 mm

80 mm

Standard product features


1200 mm.