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Cellvent HX combines the benefits of Ventform with the Cellcore HX range. It alleviates the effects of ground heave and provides an excellent gas venting medium. It is designed for use under suitably reinforced ground floor slabs. The depth is dependent upon the amount of ground heave that has been predicted.

Features and benefits:

  • Provides combined ground heave protection and gas venting capabilities in a single product.
  • Range of thickness and grades to suit most project requirements.
  • Light, robust and easy to install panels.
  • All variations include drainage slots to alleviate water pressure.
  • Unaffected by UV light and water.
  • Can be connected to the Cordek range of perimeter vents to vent hazardous ground gasses from beneath the building footprint to the atmosphere.

Related literature

The following content references this product:

Standard product features


1.2 x 2.4 m.



Dependent on the total load that will be exerted onto the panels. Consult manufacturer for information.


Dependent on many factors, including soil analysis results, soil shrinkage category, and predicted ground heave. Consult manufacturer's literature for more information.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-50-30/400 High density expanded polystyrene ventilated substructure formwork

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Cordek Ltd


+44 (0)1403 799600

Product reference

Cellvent HX


[7 / 10]
Safe load/ fail load (kN/m²), 220 mm maximum concrete depth.
[9 / 13]
Safe load/ fail load (kN/m²), 300 mm maximum concrete depth.
[13 / 18]
Safe load/ fail load (kN/m²), 460 mm maximum concrete depth.
[18 / 24]
Safe load/ fail load (kN/m²), 660 mm maximum concrete depth.


[135 mm]
[205 mm]
[270 mm]

Manufacturer details

Spring Copse Business Park,
West Sussex, RH13 0SZ
Tel +44 (0)1403 799600
Fax +44 (0)1403 791718
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