The CL:AIRE TB16 is useful guidance written by the teams at EPG ltd and Ambisense Ltd, and provides a robust and practical solution for the monitoring of under-floor voids. This method of post-construction monitoring is not routinely required, however, it can be used on sites where incorrect membranes have been installed or omitted altogether, or where specified verification has not been completed. In addition, the method can also be used for assessing larger sites, so that the ground-gas risk assessment can be further refined to potentially remove the need for membranes across the whole site.
The guidance is available as a download from the CL:AIRE site here