I want to build a free standing spiral shower stall and thought I'd run my plan past you guys and see if anyone has helpful hints. I plan on making the armature from rebar covered with concrete reinforcing mesh covered with metal lath. For the interior of the spiral I am planning on using Quickwall to insure that it is waterproof. The floor pan would be done this way, too. For the exterior surface I was thinking of using Structolite. Ideas?