Ensuring Quality: KORE Void Formers

by Brian Flax | Jan 24, 2023

KORE have been manufacturing high-quality expanded polystyrene (EPS) void formers for almost 20 years. As the first company in Ireland to achieve the updated ISO 9001:2015 Quality Management Systems & ISO 14001:2015 Environmental Management Systems certification, quality assurance is one of the most important components of our manufacturing and service process.

KORE’s EPS void formers and fillers have been used throughout the construction industry for large projects such as motorways, shopping centres, residential developments, embankments and underpasses in Ireland and the U.K . Designed to fill a void in building and civil engineering projects, void formers decrease the volume of concrete, reducing weight, while increasing the strength of concrete.

Expanded Polystyrene

KORE’s expanded polystyrene (EPS) insulation is a lightweight, rigid, closed-cell insulation. EPS is available in different compressive strengths to withstand load and back-fill forces. This closed-cell structure provides minimal water absorption and low vapour permeability. While EPS is primarily used for insulation in buildings, it can also be used for sub-structures and void-fill blocks for civil engineering, bridge, and rail & road widening schemes used in conjunction with concrete and clay.

KORE’s EPS products undergo rigorous testing for quality assurance, including density, compression strength, thermal conductivity, tensile strength, bending strength, and water absorption testing.

KORE void formers are manufactured and tested in accordance with EN 13163, and backed up by a declaration of performance for each density type, BS EN 14933:2007 specifically for void formers, which specifies the requirements for factory made products of expanded polystyrene which are used for frost insulation of roads, railways, trafficked areas, light weight fill for reduction of horizontal and vertical earth pressure and other civil engineering applications. The products are manufactured in the form of boards or blocks. The standard also covers specially cut shaped boards or blocks. Below is an example of some of the information included in a KORE Declaration of Performance Certificate, in this case EPS300 White:


Compressive strength is one of the most important aspects of KORE’s EPS void formers. According to EN 13163, the 10% compressive strength figure is the minimum figure stated at production, not as a characteristic figure. At KORE we test all our EPS in-house to confirm the material produced meets the required physical properties. We sample blocks of EPS and record the test data. By doing so, all our EPS is traceable from production to site ensuring we can confidently stand behind our product.



KORE’s EPS is available in five grades, EPS 70, 100, 150, 200 and 300, with the majority of void formers manufactured in white EPS, in the density necessary for the compressive strength needed for your project load case. The range of EPS densities available will allow you to complete the structural design requirements for your project.

The design of concrete screeds to TR34 (Concrete Industrial Ground Floors) standard, concrete specification, modulus of subgrade reaction, and factors of safety can be found in our free void former design guide which you can download.

KORE’s bespoke EPS void formers will be manufactured to your project design requirements, with many applications available including arch formers, ramp formers, road embankments, slope stabilisation, secant pile wall construction, guide wall formers and more. In addition, KORE also offer solutions for Geofoam applications, such as road widening, rail embankment, road and airport construction over poor soil and levee rehabilitation and construction, among many others.

KORE’s customers have commended our void formers for their millimetre accuracy and custom specification on project design and production. Read about some of our previous projects in our case study section.

Technical Service

KORE provide a number of complimentary technical services to all our customers, including, but not limited to:

  • U-value calculations
  • Thermal bridging analysis
  • Temperature Factor Analysis
  • Construction details
  • BCAR – CE, NSAI & Declarations of Performance Certificates
  • CPD courses, online training, on-site visits and more.

When you partner with KORE, you partner with industry experts who support and guide you throughout your project, with clear communication from planning stage to on site installation and project completion. Our customer service process will provide maximum efficiencies and savings for you and your project team.

For more information on KORE’s void formers, including design examples and case studies, download our design guide below. If you would like to speak to a member of our technical team, email us at [email protected].

Download Design Guide