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Project Information

Name : Bridgwater Performing

Main Contractor : BAM Construction

Sub Contractor : Solum SW Ltd


To provide a cost effective passive vented ground gas protection system to comply with site characteristics (CS2) requirements. Lower elements of the structure required both waterproofing protections to BS8102 and protection from high levels CO2 and Methane.

Radbar 500, a blown film of extruded low density polyethylene LDPE, is a gas barrier and damp proof membrane to protect buildings from moisture, radon,  methane and carbon dioxide from the ground, for use above or below slab in concrete ground floors which are not subject to hydrostatic pressure. when installed . When installed in accordance with the BRE report 414 “Protective measures for housing on gas contaminated land” Radbar is an effective solution and can be laid with confidence. The orange 500 μm Radbar membrane is suitable for NHBC Amber 2 Applications.  The Radbar Gas Membrane is satisfactory for use as a gas resistant barrier to restrict the ingress of radon, methane and carbon dioxide gases into a building from landfill and naturally occurring sources above or below the ground floor slab.  The membrane can be used in reinforced cast in-situ (ground — supported) concrete floors, suspended beam-and-block concrete floors and precast concrete slabs.

Other products specified by atal include:

  • atal Gasflow 25 – Venting system to allow passive ventilation of ground gasses below slab.
  • atal Bentofix 5300 – Sodium Bentonite membrane, BBA certified protection against groundwater and methane
  • atal Premsil GMA – Gas resistant self adhesive membrane to terminate into DPC.
  • atal Liquid Gas Barrier – Coating for difficult detailing.


A robust cost effect system in which the installer was provided with atal on site training and regular visits and inspections to ensure installation was in accordance with atal design and data sheets, avoiding a poor installation.