T
Tile Shop
Never been a fan of paint on or stick on membranes as weight issues come into the equation.
I had an enquiry about this a while back. I found out that the BAL WP1 has its own limit of 32Kg's psqm regardless of the substrate (the standard substrate limits would override that, so still only 20kg if tanked onto plaster). But the BAL Tank-it, Ardex WPC, Mapegum WPS and the Norcros Wet Seal, all match the substrate limits.
If a wall needed replacing though, I'd opt for wedi, marmox or kerdi-board as it would cut out the need for a "middle man".