Build the concrete block double skinned wall using wall ties (and probably filling the cavity with foam?
4. Apply 2 tanking coats to the exterior of the walls making sure that the bottom of the wall is painted right down to the base tanking coat 5. Apply some kind of protection sheeting to the exterior walls such as a thin polystyrene sheet to protect the tanking layer, then back fill with soft earth or sand As the span of the hole is 6m x 8m I guess I would have to install block and beam or perhaps steels at ground floor level to stop the walls leaning in over time, but my main questions are whether the above method is the correct way to tank a basement using tanking paint, whether this method is the cheapest in my situation and I would also like confirmation that you can build walls directly from the concrete base. I always thought there was a requirement for the foundations sit independant from the floor slab to allow for movement but I guess movement is exactly what you do not want on a sealed basement. Thanks for your help and sorry the question is so long.
