Situation is bathroom with shower cubicle. Off the shelf shower tray (stone resin?) 170 x 80cm. Two shower walls are in finish plaster on brick, 3rd wall will be glass onto tray base. Remaing side will be open with no door. Floor is concrete, with prowarm insulation boards (waterproof they say)+ loose wire underfloor heating. Floor and walls to be tiled. Questions: 1 tanking for the 2 shower cubicle walls, membrane system or paint on? 2 does the floor need tanking under tray, or if using membrane system in step above that goes down and rests on tray base, is that sufficient 3 wasnt going to tile inder tray, or should that be done? 4 the rest of floor, does this need tanking? 5 if so, where should the tanking fit in, considering the concrete floor needs: insualtion boards, self levelling and loose wire UFH. Id guess tanking if needed goes on top of levelling compound then install UFH over this?