Ventilation behind tanking membrane?

[trenelly]

I have a damp retaining wall in the back of the ground floor of my house. I would like to use a tanking membrane to stop the damp coming into the room but do not think there is sufficient water coming through the wall to requ ire a drain and sump approach. Can I just ventilate the area behind the tan king membrane?

[harryagain]

There are patented systems to use for this circunmstance. Primarily intended for cellar conversions. Google:- waterproofing+cellars.

Or your builders merchant will have info.