Hi I need some info for laying methane gas membrane to stop landfill gases.Question is does this membrane will over lap external wall as well over DPC making a bridge.Will anybody help and explain the best way to lay this.Regards
The gas membrane should be laid horizontally under the extent of the slab i.e. how you would fit a carpet in a room. You should then use a gas resistant dpc which should be laid across the cavity and brought down the inner leaf of the block/brickwork. This is then taped to the gas membrane.
Standard details are available on A.Proctor Group website Google "proctorgroup.com" I have been involved in the gas protection industry for over 15 years and run my own consultancy designing gas venting and membrane systems as well as being inputting into some of the guidance like ciria665.