CL:AIRE is pleased to announce that a new Technical Bulletin TB16: Complete Continuous Monitoring in Underfloor Voids is now available to download here>>>>>>.
Post construction monitoring of passively ventilated underfloor voids is not routinely required. The design and performance of passive venting systems for ground gas follows well established principles and has been proven to be effective over the past twenty five years.
There are however occasions when there is value in carrying out monitoring of underfloor voids to help provide a more robust assessment of the risk posed by ground gas on a site. In such cases this bulletin explains a best practice approach using complete continuous monitoring. Complete continuous monitoring refers to the complete data set required to assess the performance of ventilated voids. The data includes gas concentrations in the void, and meteorological data that is obtained each time a gas reading is taken. Note that this is different to the complete continuous monitoring data in boreholes, which also requires the continuous measurement of borehole flow rates.
By collecting meteorological data alongside the gas concentrations in the void, the design calculations can be verified.
It has been written by Steve Wilson - EPG Ltd, Fiachra Collins - AmbiSense and Leo Phillips - enitial.