Bi-Foam foamed glass structural sub floor insulation 1.5m3 bag (similar to TECHNOpor®)

Bi-Foam foamed glass structural sub floor insulation 1.5m3 bag (similar to TECHNOpor®)

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Although priced Bi-Foam is not available to buy online due to variations in haulage costs normally determined by site conditions, access etc please call us for an instant quote on haulage for anywhere in the UK

Bi-Foam is an aerated glass foam granulate insulation product manufactured from 100% recycled glass it is lightweight having a loose bulk density typically 170 kg/m3.

Typically used for...

  1. Load bearing thermal insulation beneath floor slabs and providing a complete replacement for traditional hard-core, blinding, over site concrete and expanded polystyrene insulation construction or precast beam and block and polystyrene insulation flooring.
  2. Load bearing thermal insulation beneath foundations

Price £131.25 (plus Vatper 1.5m3 bag - calculate the volume you require using the charts below or call us and we will do it for you.

Please contact us for a site specific haulage cost - We offer FREE DELIVERY on bulk orders and full loads*

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Since its commercial introduction in 2007  over 600,000 cubic metres of Bi-Foam has been installed on over 2,500 projects.


Bi-Foam features

  • Eco friendly insulation for floor construction
  • Ideal foundation for low energy housing
  • Simple clean and quick to install
  • Perfect for difficult access projects
  • Independently approved load bearing and thermal properties (DIBt, LABC)
  • Lower cost than traditional floor construction
  • Manufactured form 100% recycled waste glass
  • Low embodied carbon
  • Sustainable
  • Lightweight
  • Easy to handle
  • Reduced construction time / costs
  • No matrix required
  • No curing time

Bi-Foam is supplied in 1.5m3 bags. Each bag is £131.50 ex VAT and haulage. This equates to a material cost of £87.67 per m3. 

Whatever size order please call us for a haulage quote, we will always be able to get the best rate for you by quoting job by job, site by site.

For larger orders 1.5m3 bags can also be delivered in full loads on a single lorry, the lorry carries 48 bags equivalent to 72m3of Bi-Foam

*Bulk deliveries are available but a minimum order of 91m3 is required. this is the equivalent of 61, 1.5mbags. The site must also be able to accept an articulated lorry as the Bi-Foam is supplied by a walking floor vehicle.

We offer considerably reduced haulage rates for bulk deliveries - Please call for pricing -for some postcodes for the south east and south of England bulk orders will be delivered free.

Product information


  • Bi-Foam is formally approved as a load bearing thermal insulation material for use in conjunction with the construction of permanent buildings.
  • Bi-Foam provides both the structural base and insulation to ground bearing floors. As such it replaces the use of granular sub-base, sand blinding, concrete over site and insulation. Where suspended ground floors are envisaged, other than those where a ventilated void is required in conjunction with heave associated with clay soils due to the presence of trees, Bi-Foam can be used to replace the typical precast pre-stressed concrete floor beams and block infill.
  • For low energy buildings including domestic houses and low rise commercial buildings Bi-Foam can be used to provide insulated foundations thus avoiding the thermal bridging and heat loss associated with typical cavity insulated walls and insulated flooring via the internal masonry skin which forms a ‘break’ in the insulation. Moreover the floor construction is able to be included in the thermal mass of the building.
  • Bi-Foam provides drainage and can be used in SUDS design.


  • Bi-Foam provides overall economy when compared to other forms of floor construction.
  • The use of Bi-Foam can result in a reduction in the overall construction programme enabling a building to be occupied earlier and in the case of a commercial building result in an earlier generation of income.
  • The benefits of the use of Bi-Foam are recognised resulting in its increasing use notably some 150,000m3 in 2013. 


  • Bi-Foam has a weight of a tenth of that of traditional building materials being only 170kg/m3. As such it is easier and quicker to handle and place requiring less labour and plant.
  • Following the usually undertaken excavation and trimming to formation, a geotextile separating membrane is simply laid on the natural formation prior to placing and spreading Bi-Foam . Compaction of Bi-Foam is easily undertaken via a vibrating plate compactor i.e. 3 passes per layer.
  • Bi-Foam can be used in all weather conditions and is not affected by rain, snow or freezing conditions unlike typical granular sub-base materials which can become un-usable due to excessive moisture due to rainfall or frozen.
  • There is no cutting to form the thermal insulation layer which eliminates offcut waste.
  • Operatives are not exposed to dust particles which can arise when expanded polystyrene type materials are cut via saw which can result in irritation to eyes and require the use of respiratory protection to prevent entry into lungs.
  • Bi-Foam does not degrade and can be re-used.


  • Bi-Foam is manufactured from 100% waste glass which would normally be deposited in land fill.
  • Energy used in the manufacture of Bi-Foam is provided by hydro-electricity.
  • Bi-Foam has low embodied carbon.
  • The use of Bi-Foam  reduces the use of diminishing natural re-sources.
  • The use of Bi-Foam reduces pressures on the environment in man’s pursuit of new sources of natural materials.
  • Unlike expanded polystyrene or other insulation materials surplus Bi-Foam does not need to treated as a waste material and deposited in land fill. It can be used as general fill or beneath paving, footpaths etc. further reducing the pressure on land fill.
  • Bi-Foam is a sustainable material.
  • Bi-Foam can be used as an alternative to concrete for foundations and the ‘concrete free house’ foundations can be installed in all 52 weeks of the year because Bi-Foam is unaffected by cold weather.

More than ten years ago various universities in Germany, Switzerland and Austria carried out research into the possibilities of using waste glass to create a useful product. They looked at a method of aerating molten glass to create a pumice like granulate.  The glass was pulverised and heated to a gel once molten the glass gel was aerated and allowed  to cool to form grey granulate sheets which naturally broke into smaller pieces (granulate).  The granulate was light as volcanic pumice (170Kg/m3) yet had very high compressive strength (500kN/m2) the enclosed  bubbles created  excellent insulation properties (Lambda of 0.085W/mK) at the same time the closed cell surface of the granulate prevented moisture absorption by capillary action.

The granulate is also

  • Non toxic
  • frost proof,
  • fire proof
  • Dimensionally stable
  • resistant to age degradation

Uses of Bi-Foam include:-

  • Load bearing thermal insulation beneath floor slabs and providing a complete replacement for traditional hard-core, blinding, over site concrete and expanded polystyrene insulation construction or precast beam and block and polystyrene insulation flooring.
  • Load bearing thermal insulation beneath foundations
  • Light weight fill for embankments

U-Values achieved using Bi-Foam


U – Values

(W/m2K) (mm)

Loose thickness


Compacted thickness


























NB "Bi-Foam placed at 455 mm uncompacted, 350 mm compacted (1.3:1), achieves a u-value of 0.22.  Lower u-values are achievable by increasing depth of Bi-Foam ."

Design considerations/requirements:-

  • For sub-soils that are not free draining i.e. cohesive (clay) soils, drainage is to be provided. See specific Project design drawings/details.
  • If the natural standing ground water level is less than 300mm below the base of Bi-Foam a capillary moisture barrier is to be provided.
  • The formation level is to be trimmed and any loose material removed to provide a uniform surface and ensure a uniform thickness of Bi-Foam throughout. Inspection/approval of formation as required.
  • A non-woven geotextile 150gm/m2 separation membrane is to be provided which is to be wrapped up the edges of the completed Bi-Foam and lapped with the surface geotextile – see below
  • A non-woven geotextile 150gm/m2 separation membrane is to be provided to the compacted surface of Bi-Foam .
  • When using Bi-Foam in conjunction with insulated foundations it is good practice to extend the Bi-Foam beyond the face of the foundation to allow effective load dispersal and ensure the presence of properly compacted material beneath the foundation.
  • Foundation bearing strata to be verified as normal.
  • The maximum imposed stress applied to Bi-Foam must not exceed the nominal value for compressive stress as provided in table 1 above.

When assessing settlements of foundations, in addition to anticipated settlements of the foundation soil(s), deformation of Bi-Foam should also be considered and assessed in accordance with the constrained modulus provided in table 1 above.

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Bi-Foam  is chemically inert and complies with requirements for Environmental Compatibility.

Bi-Foam  does not present any hazard to the Health and Safety of persons involved with its installation or use.

Bi-Foam  is non-combustible, frost resistant, self- draining and unattractive to vermin.

Table 1. Design characteristics of Bi-Foam

Nominal Value for compressive strength



Nominal value for compressive stress

fcd = fc,nom/Ƴm . α


Constrained modulus of the thermal insulation layer




560 kPa

270 kPa

6000 kPa


See Technical data sheet for full details



Design thickness of Bi-Foam 

Bi-Foam  requires the same formation level preparations that are necessary for normal construction tolerances

  • Minimum compacted thickness 150mm.
  • Maximum compacted layer thickness 300mm.
  • For design thickness greater than 300mm, placing and compaction is to be undertaken in two or three layers.
  • Maximum compacted thickness beneath floor slabs and foundations 900mm.
  • Compaction ratio i.e. loose to compacted state 1.3:1.

Installation for New Build complete floor and foundation




Installation for refurbishment of existing floor



Installation general schematic for installation of Bi-Foam 



For more technical information and installation options and drawings please see downloads below



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Regular Price: £150.00

Special Price £145.00

Availability: In stock