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Design of ground gas protection in new build

This training course (delivered via 2 x Zoom sessions) is based around the requirements of BS8485 for new buildings. It would aim to dispel the myth that gas protection design is just adding up numbers of points and obtaining warranties from suppliers. This is a major cause of problems in the industry.

Course fees

£325 + VAT (£390) full CIRIA member and LACL members
£375 + VAT (£450) Non members

20-21 May 2024
13.00 – 16.30 Zoom sessions daily.
Delegates must attend and complete BOTH sessions fully to gain 6hrs CPD. Delegates are requested to log in 10 minutes prior to each session start time. 


Designing ground gas protection systems following the guidance in BS8485 is more than just adopting a Characteristic Situation and adding up points.  It requires a detailed justification for any gas membrane and calculations for any underfloor ventilation system that is specified.  The points assigned to the floor construction should also be justified. The design should be summarised and explained in design report and shown on detailed site specific drawings for construction.  

This training will explain in detail the factors to be considered and how to complete the appropriate venting calculations.   It will explain the details to be included in a design report with reference to relevant clauses in BS8485. The standard also recommends that the design report should include the verification plan for the proposed system.  The course will also explain when Detailed Quantitative Risk Assessment (DQRA) might be used in place of the simple empirical points system.

CIRIA is a delivery partner for this training from EPG Ltd.

Who should attend
Anyone who procures, designs or approves gas protection systems.  This would include developers, contractors, consultants, NHBC and local authorities

Why attend
  • Gain an overview of the contract for gas design, roles and responsibilities
  • Understand BS8485 points system – where and when it can be used
  • Learn design considerations for concrete floor slabs and basement walls for gas resistance and BS8485 points
  • Explore design, detailing and specification of gas or VOC membranes – how to assess durability, permeation of gases other than CH4 and CO2, VOCs 
  • Review gas detection systems – what are they for and critical factors eg detector head locations
  • Explore design for future changes in gas regime
  • Undertake Ventilation design calculations 
  • Understand the design report and verification plan
  • Share experiences and knowledge with our expert trainers and other delegates
  • Gain CPD. 


This course has a value of 6 hours towards your CPD. Certificates will be sent to delegates following completion.

This training will be delivered via Zoom sessions. 


If you are unable to book online, please complete and return the booking form to Nipa Patel by email. 

Notice for new bookings from EU/EEA customers only
CIRIA is currently unable to directly process your transaction if you are purchasing from the EU/EEA region. If you wish to book this training course please email your request to [email protected] in the first instance.

Terms and Conditions
Click here for details of our terms and conditions that will apply.
Personal data is gathered in accordance with CIRIA's privacy policy. 

Further information

For further information on CIRIA membership and other services, please contact:
Email: [email protected]

5/20/2024 1:00 PM - 5/21/2024 4:30 PM
GMT Daylight Time

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