Permavoid Geocellular System

The Permavoid system comprises of high strength modular cells suitable for sub-base replacement, plus components that incorporate silt / oil treatment and shallow flow controls into the system.  

It can be used in place of a traditional aggregate sub-base within trafficked pavements, providing a unique high strength, consistent structural raft in accordance with BS7533-13:2009. The geocellular structures have a void ratio up to 95%, greatly enhancing the pavement's attenuation capacity and reducing aggregate requirements in hydraulic pavements. The system is suitable beneath asphaltic, block-paved or concrete pavements and for the full range of traffic conditions from domestic driveways to highways.


Features & Benefits


  • Designed and tested for retention, attenuation or infiltration at shallower depths
  • Effective source control
  • Can be installed above a high water table
  • Allows water to spread across a site
  • Ideal for brownfield or contaminated sites
  • Can remove silt and hydrocarbon deposits
  • Removed the requirement for pumping stations
  • Oil interception at source, no petrol interceptors
  • Integrates with Polystorm geocellular solutions for deeper applications
  • High compressive and tensile strength under load
  • Suitable beneath both porous and non-porous surfaces
  • Reduces excavation depth and cost
  • No need for trench supports or associated plant



  • Geocellular Water Management Systems

    Find out more about our widest range of geocellular water management solutions to meet the requirements of sustainable drainage systems (SuDS) across an extensive variety of applications.

  • Applications

    The Permavoid system is designed to be used in place of traditional aggregate sub-base, providing a unique, high strength, consistent structural raft with all the benefits of a high voided modular geocellular structure.

  • System Components

    The Permavoid System comprises of a number of components which may be utilised within a SuDS design



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Permavoid Technical Bulletin Issue 1 - Shallower Installations

pdf (1.49 MB)

Permavoid System Technical Manual

pdf (7.13 MB)

Project examples

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  • Walthamstow Stadium: Project complete

    Before 294 homes could be built to create one of London’s most prestigious new developments, stormwater run-off problems at the former greyhound track site in Walthamstow needed addressing as part of the...

  • Greenwich Wharf: Innovative water management

    Greenwich Wharf wasn’t designed purely for financial gain. The site required careful design consideration to mitigate any flood risks. With a scheme of this size, especially riverside, rainwater...

To view and download technical information relating to the Permavoid geocellular system, including datasheets, Standard Details and our Permavoid Technical Manual, please follow the link below to our Technical Hub.
Technical Hub