90mm Cellcore HX S Under Slab (EPS) Anti Heave Board is purpose-built for placement beneath reinforced concrete floor slabs, delivering dependable defence against ground heave movement. This 90mm cordek hxs incorporates a cellular construction from Expanded Polystyrene, carefully engineered, formed, and tested to achieve exact performance standards.
Brand: Cordek®
Model: 90mm (Grade 24/32)
Thickness: 90mm
Length: 2400mm
Width: 1200mm
Coverage: 2.88m2
Grade: 24/32
Standard Panel: 2400mm x 1200mm
Beams Widths: 2400mm x 1200mm to 300mm (in 25mm increments)
Material: (EPS Insulation) Expanded Polystyrene
Shipping method: Rigid Vehicle ǀ Courier
Applications: Reinforced concrete floor slabs
BBA Certified: Yes
Maximum depth of concrete: 900mm
Safe load: 24 kN/m2
Shrinkage Category: Low
Plasticity Index: 10-20
Fail load: 32 kN/m2
Features: Durable ǀ 4th Generation ǀ minimize wastage
Manufacturer: 90mm Cordek Cellcore HXS®
This anti-heave solution functions as a protective barrier beneath reinforced concrete floor insulation slabs, reducing the impact of ground heave by restricting the upward transmission of forces to your structure.
The 90mm Cordek Cellcore HXS Grade 24/32 anti-heave board has been engineered and tested for concrete depths up to 900mm, with proven performance credentials meeting all specified requirements.
Our range includes various depths and grades tailored to typical soil heave scenarios and concrete specifications. We also supply specialist variants for pile cap and ground beam applications, plus options with integrated insulation, permanent formwork, or passive gas venting.
The 90mm Cellcore HX S range protects reinforced concrete floor slabs from upward movement caused by ground heave effects.

For concrete thicknesses between 1220mm and 2000mm, further grades of Cellcore are available. For further advice please contact the InsulationBee Technical Team on 02038839057 / 02038839057.
Each 90mm Cellcore hxs grade is engineered to support a specific concrete thickness, plus an allowance for live loads of 1.5 kN/m², with minimal creep compression over a 16-hour curing period. This is defined as the "SAFE LOAD."
When the load reaches the predetermined threshold, the polystyrene legs of the 90mm Cordek panels will buckle and fail as the ground beneath moves upward—this is known as the "FAIL LOAD."
During design, ensure the slab, beam, or pile cap can accommodate the difference between its own weight and the fail load, as shown in the design examples on the following page.
Browse our Cordek range and filter by thickness or coverage using the left-hand menu. To discuss product suitability for your project or request a quantity discount quotation, call us on +4402038839057, email sales@insulationbee, or use Live Chat - Lowest UK Insulation board Prices.










