Achieving best value through design of ground gas protection

Steve Wilson, Technical Director, EPG Ltd and CIRIA trainer discusses the importance of design of ground gas protection in helping clients and contractors achieve best value. 

In recent years the importance of verification of gas protection measures has been recognised and is becoming more robust. However, it is not possible to verify gas protection unless there is a design in place. BS 8485 requires a design report and design drawings to be prepared prior to installation and this would include the verification plan. A collection of suppliers standard details is not a design, site specific details and layouts are required based on the structural design or architects drawings. 

Guidance on what is needed in a gas protection design is provided in the NHBC Foundation Report NF94. For simple houses the design must include a drawing showing the location of air bricks providing ventilation to an underfloor void. 

For clients and contractors the best value is achieved if the design of gas protection is completed prior to tender by an independent consultant, it is difficult to price something before you have designed it and suppliers and installers often over specify products!

There is also poor understanding of ventilation performance in the industry. Ground level vents linked to geocomposite void formers below a slab will not provide effective venting below large warehouse buildings. 

Geo-environmental consultants are often best placed to advise the client on design and should embrace this opportunity. Join the Design of ground gas protection measures in new buildings training on 20-21 May 2024 and learn the vital aspects of design – important whether you are the designer or approving designs for your clients.

CIRIA is a delivery partner for EPG Ltd for this training and the course is delivered by Steve Wilson, who is co-author of the NHBC Foundation Report NF94 guidance.