Home > Companies > FOAMGLAS® > 1.1.2 Floor Insulation (load bearing) with Waterproofing Membrane beneath Structural Slab


  • Waterproof.
  • High compressive strength without deflection or movement.
  • Non-combustible.
  • Impervious to water and water vapour.
  • Sealed cellular structure.
  • Dimensionally stable.
  • Acid resistant.
  • Easily cut to shape.
  • Resistant to vermin.
  • Recycled content scrap glass: Minimum 60%.
  • Ozone Depletion Potential (ODP): <1%.
  • Global Warming Potential (GWP): Zero.
  • GreenSpec rating, see 'Cellular Glass' or 'Foamed Glass'.
  • Green Guide rating, see 'Cellular Glass'.


  • Quality: Systems with high quality materials; management by systematic site inspections and professional consulting.
  • Cost efficiency: The high durability preserves maximum value and ensures minimal maintenance costs.
  • Sustainability: Optimum insulation performance and protection against moisture for future generations. Scrap can be reclaimed and re-cycled to make new Foamglas.
  • Insulation performance: Insulation performance is permanent; ageing does not take place. Use above and below ground, unaffected by moisture, humidity and compressive loads. Proven to retain its thermal and vapour control characteristics for ˃ 50 years.
  • No thermal bridging: Fully bonded insulation system, zero fixings prevent thermal bridging, and exposed fixings.
  • Non-toxic: Foamglas cellular glass contains no toxic substance, does not contaminate water or the ground, in cases of fire, does not develop fumes or toxic gases.
  • Sealed structure and non-hydroscopic: Each cell has a glass wall, giving the unique structural strength, vapour tight and non-hydroscopic properties.
  • A separate vapour barrier is not required: With its purpose manufactured adhesives, Foamglas is suitable for extreme humidity environments and gives control of the vapour drive in any direction. Foamglas is an insulation and vapour barrier in one single material.
  • High compressive strength: Capability to withstand high compressive loads without deflection or movement.
  • Dimensional stability: Very low rates of thermal movement, mechanical fixings are not required to prevent delamination from the parent structure.

Foamglas recommended build-up:

  • Primary layer: Compacted hardcore or subsoil.
  • Lean concrete mix.
  • Levelling material: Chippings, stabilized sand, or liquid mortar.
  • Foamglas insulation.
  • Bituminous waterproofing membrane.
  • Separating layer.
  • Concrete slab.

Standard product features


  • Thermal performance is permanent and never changes.
  • Manufactured from recycled glass (minimum 60%) and natural raw materials which are available in abundant supply - sand.
  • The insulation is totally inorganic, contains no ozone depleting propellants (CFCs, HCFCs etc), flame resistant additives or binders; VOC or other volatile substances.
  • For substrate quality and suitability, see Technical Guide TG1.

Foamglas® Ready Board (T4+):

  • Density (EN 1602, ± 10%): 115 kg/m³.
  • Length (EN 822, ± 5 mm): 1200 mm
  • Width (EN 822, ± 2 mm): 600 mm.
  • Thermal conductivity (EN ISO 10456): ≤ 0.041 W/m·K.
  • Reaction to fire (EN 13501-1): Core material Euroclass A1.
  • Compressive strength (EN 826 annexe A): ≥ 600 kPa.
  • Flexural modulus of elasticity (EN12089): 700 MN/m².
  • Bending strength (EN 12089): ≥ 450 kPa.
  • Tensile strength (EN 1607): ≥ 100 kPa.
  • Thermal expansion coefficient (EN13471): 9 x 10-6 K.
  • Impervious to water vapour (EN ISO 10456): µ=∞ infinity.
  • Ozone Depletion Potential (ODP): <1%.
  • Global Warming Potential (GWP): Zero.
  • Green Guide Rating A.
  • GreenSpec listing see 'Cellular Glass' or 'Foamed Glass'.
  • Manuf to Environmental Management System ISO14001.
  • CEN Keymark: 001-BK-516-001-0029-T00A.
  • CPR DOP: 120200015.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-45-50/325 Cellular glass insulation board

Product specification

An important note about specifying





+44 (0)20 7492 1731

Product reference

1.1.2 Floor Insulation (load bearing) with Waterproofing Membrane beneath Structural Slab


 - Type:

Foamglas® Ready Board (T4+)

 - Thickness:
[40 mm]
[50 mm]
[60 mm]
[70 mm]
[80 mm]
[90 mm]
[100 mm]
[110 mm]
[120 mm]
[130 mm]
[140 mm]
[150 mm]
[160 mm]
[170 mm]
[180 mm]

Manufacturer details

31-35 Kirby Street,
Hatton Garden,
London, EC1N 8TE
Tel +44 (0)20 7492 1731
Fax +44 (0)20 7492 1730
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