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


Data Sheets

Product Issue Date Version Size Download
Filcor Data Sheet 03/2021 8 405.9 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 09/2019 2 404.6 KB

NBS Clauses

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

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