Permavoid Limited

Permavoid 150mm Geocellular sub-base replacement

Permavoid 150mm

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Permavoid 150 is a 150mm thickness modular interlocking plastic storage system designed for use as a combined drainage component and sub-base replacement system. It has exceptionally high compressive strength and bending resistance within joints and creates a horizontal structural ‘raft’ within the pavement that is ideal for the shallow attenuation and conveyance of surface water.

The overlying pavement layers can be as slender as 130mm and the overall pavement as slender as 280mm, depending on the nature of traffic loading and underlying soil CBR values; the modular layer also insulates the pavement and avoids frost problems even in pavements less than 450mm thickness. The modules have a very high void ratio (95%) providing highly efficient water storage capacity.

Key Features

  • Facilitates Shallow construction, minimises residual excavated material
  • Large surface area to depth ratio provides exceptional infiltration performance, in turn reducing attenuation volume requirement
  • Satisfies designers’ risk assessments in accordance with CDM
  • Manufactured from recycled material and also recyclable
  • Unique jointing system (Permatie) provides creep resistance
  • Provides a high strength rigid raft for construction
  • Lightweight and easily handled (3Kg per unit)
  • Replaces sub-base, minimises the requirement for imported aggregates


  • Sustainable Drainage Systems (SUDS)
  • Sub base replacement
  • Stormwater infiltration
  • Stormwater attenuation
  • Ground stabilisation
  • Podium decks
  • Tree irrigation