Filcor - Void Formers

Filcor (Expanded Polystyrene) is commonly used as a lightweight material for forming openings and voids within concrete structures. The use of Filcor void formers reduces the weight of the structure when left in-situ or alternatively can be used for temporary applications as part of a formwork system.


  • A range of compressive strengths available
  • Lightweight and easy to handle
  • Available as standard sheets or blocks
  • Can be profiled to customer requirements
  • Provides a high degree of insulation
  • Flame Retardant (FR) properties

The versatility of Filcor means that any shape, size or profile can be manufactured with relatively short lead times. In addition, a range of materials of increasing compressive strengths are available to meet the loading requirements of the application, whilst also providing the most cost effective solution.


Filcor can be used for a variety of void forming applications for the formation, shaping and positioning of openings to reduce the weight of concrete structures. The product can be manufactured in standard sheet sizes or alternatively profiled to the installer’s exact requirements.


Physical Properties:

Manufactured BS EN 13163:2012 Physical PropertiesFilcor 20Filcor 45Filcor 70Filcor 90Filcor 100Filcor 120Filcor 140Filcor 160Filcor 190
Compressive Strength at 1% strain (kPa)20457090100120140160190
Nominal Density (kg/m3)152025303540455055
Thermal Conductivity Value +W/mK0.0380.0360.0350.0340.0330.0330.0330.0330.033
Other Data
Max Depth of Concrete (assumed 25k/N/m3) to not exceed 
Compressive Strength at 1% strain (mm)

Filcor complies with both BS EN 13163:2012 and BS EN 14933:2007

Environmental facts about Filcor EPS

The manufacture of Filcor is a low pollution process. Steam is he key component and the water is re-used many times. There is no waste in the process as all cut offs or rejects are recycled.

Filcor is 98% air. This makes Filcor a uniquely resource-efficient material with small carbon footprint.

Filcor is HFC, CFC and HCFC free and Pentane is used as its blowing agent. Pentane has a low Global Warming Potential* (GWP) of less than five. (The EU does not register pentane as a substance hazardous to human health or environment.)

Styrene, used in the manufacture of Filcor, occurs naturally in many commonplace items including strawberries, beans, nuts, beer, wine, coffee beans and cinnamon

* Global warming potential (GWP) is a means of measuring the strength of different 'greenhouse' gases in the atmosphere and can be used to define the impact greenhouse gases have on global warming over specified periods of time. As an example CO has a GWP of 1 over 100 years. All other greenhouse gases HFC, CFC HCFC and methane are measured relative to CO2.
Filcor Recycling
Filcor is 100% recyclable. As a single polymer, Filcor is straightforward to recycle and is recyled into items such as replacement hardwood decking or garden furniture and coat hangers


Data Sheets

Product Issue Date Version Size Download
Filcor Data Sheet 01/2024 10 412.3 KB

MSDS Data Sheets

Product Issue Date Version Size Download
Expanded Polystyrene MSDS 06/2017 5 137.3 KB


Product Issue Date Version Size Download
Construction Solutions 01/2020 2 6.6 MB

Installation Guides

Product Issue Date Version Size Download
Filcor Installation Guide 112023 3 327.3 KB

NBS Clauses

Our NBS Clauses are hosted on the external website - view NBS Clauses

BIM Library

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