> Question for those that may know: must tanking be on the
> > outside of the wall, or is it quite qworkable to waterproof
> > the inside? I'm thinking of wall deterioration and possible
> > freezing while wet.
>
> My reseach suggests that on the outside the water pushes the
> tanking onto the wall, and on the inside it pushes it off.
Unless there's a head of water (water running in), which requires considerable specialist skill to deal with, tanking is done inside - a DPC such as bitumen emulsion is applied, blinded, and a light render or plaster applied.
J.B.