Cellcore HX S

Cellcore HX S is designed for use beneath reinforced concrete floor slabs to protect against the potential effects of ground heave. The product consists of a cellular construction of Filcor EPS (Expanded Polystyrene) which has been designed, moulded and tested to tight tolerances to achieve the specified performance characteristics.


  • Reduces the upward force transmitted to the structure from ground heave
  • Wide range of profiles and grades to suit most applications
  • BBA certified
  • Meets the NHBC’s Technical Standards
  • Moulded production for enhanced and consistent performance
  • Available with integral EPS insulation, permanent formwork for ground beams or passive gas venting
  • Patented Product Technology

The standard range of products are available in a variety of depths and grades to suit most commonly encountered combinations of soil heave potential and concrete depth. Variations of the product are also available for use under pile caps and ground beams or alternatively where integral insulation, permanent formwork or passive gas venting is required.


The Cellcore HX S range is designed to protect reinforced concrete floor slabs from the upward forces associated with the effects of ground heave.


Firstly the depth of the Cellcore HX S panel should be determined by the heave potential of the soil, as detailed in table one below:

Table One: 

Results of Soil Analysis NHBC Category

Predicted Ground Movement or BRE/NHBC requirement

Depth of Cellcore HX required to achieve 'Equivilant Void'
Plasticity Index Shrinkage Category Void Dimension (mm) HX S (mm)
10-20 Low 50 90
20-40 Medium 100 160
40-60* High 150 225

Table two:

Grade * Safe Load (kN/m2) Fail Load (kN/m2) Maximum Concrete Depth ** (mm)
7/10 7 10 220
9/13 9 13 300
13/18 13 18 460
18/24 18 24 660
24/32 24 32 900

* For easy identification the panel labels are coloured as shown.

** Based on the Eurocode and a live load allowance of 1.5kN/m2.

For concrete thicknesses between 900mm and 2000mm, further grades of Cellcore are available. For further advice please contact the Cordek technical team on 01403 799600 .


d Data Sheets

Product Issue Date Version Size Download
Cellcore HX Data Sheet 01/2016 3 1.1 MB

D MSDS Data Sheets

Product Issue Date Version Size Download
Expanded Polystyrene MSDS 10/2015 2 66202

c Certification, Approval & Guidance

Product Issue Date Version Size Download
BBA Certificate - Cellcore HX 08/2011 - 379.6 KB

n NBS Clauses

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

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Request A CPD

Cordek offers a comprehensive Continual Professional Development (CPD) Seminar for engineers and architects. Our technical experts are happy to visit you at your convenience to hold a CPD session.

The presentation lasts approximately 45 minutes, with additional time for questions, and covers the following topics:

  • Ground Heave Solutions
  • VOC & Ground Gas Protection
  • Structural Fill Solutions

If you would like to request a CPD then please fill out the form below or give us a call.

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