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Project updates April 30th 2026

Project Update: Radon Protection Successfully Verified at Dursley, Gloucestershire

Abbie Ward Author

We are pleased to share the successful completion and verification of radon protection works on a residential development in Dursley, Gloucestershire.

The development is located within an area identified by UK Radon maps as having a 10–30% radon potential, requiring full radon protection measures. To meet this requirement, RIW Gas Seal Black Membrane was specified and installed across the project by Speller Metcalfe Ltd.

Independent verification was carried out by John Cornish TGPV, Cameron Jones, Harry Martin and Alfie Manton. In total, eight verification visits were completed, covering key areas of the development including:

  • Plots 1–13: DPC and perimeter tanking
  • Plots 1–13: Infill areas

Verification was conducted using a combination of visual inspection, mechanical point stress testing, and air lance testing. Any defects identified during inspections were promptly remediated by Speller Metcalfe Ltd, with all plots subsequently achieving full sign-off.

Final Status

  • Compliance: Fully compliant with CIRIA 735 and BRE Report BR211
  • Defects: All identified faults successfully remediated
  • Completion:  The radon protection system has been verified as compliant, reflecting a good standard of installation throughout the project

This successful outcome highlights the importance of robust installation practices and thorough independent verification in delivering compliant and reliable radon protection systems.