I have used regular Oxy-Clean powder on my shower floor to get it white again and it worked pretty well. Just sprinkle the powder on the floor, wet it enough to form a paste, scrub it lightly, let the paste sit on the floor for about 20 minutes, then rinse. Good luck.

Okay-- concerning 2 vs 3 2x4's, I don't really see a problem with it. it'd be a little unorthodox, but you could actually "form" the shower pan with the 2 2x4's, and then bring the mud pan all the way to the top (including cement board on top of the 2x4's). Use a Kerdi drain, and either Kerdi Membrane of Laticrete Hyroban liquid membrane (either way, a surface applied shower pan), and just make an elevated curbless shower base, mounting your glass over the 2x4's. if you want to have some sort of curb, though, I would strongly suggest going up the third 2x4, or you're going to have a very small piece between the top of the curb and the top of the shower floor. You really want to have a little bigger piece-- won't collect "junk" as easily. As for your shower pan question, Below is a link to the step by step construction of a standard shower pan. Additionally, For the standard pan, if the plumber's going to install it, and he balks at the thought of a preslope under the pan membrane, you can show him this: Uniform Plumbing Code related to shower pan construction. "412.8 When the construction of on-site built-up shower receptors is permitted by the Administrative Authority, one of the following means shall be employed: (1) Shower receptors built directly on the ground: Shower receptors built directly on the ground shall be watertight and shall be constructed from approved type dense, non-absorbent and non-corrosive materials. Each such receptor shall be adequately reinforced, shall be provided with an approved flanged floor drain designed to make a watertight joint in the floor, and shall have smooth, impervious, and durable surfaces. (2) Shower receptors built above ground: When shower receptors are built above ground the sub-floor and rough side of walls to a height of not less than three (3) inches (76 mm) above the top of the finished dam or threshold shall be first lined with sheet plastic*, lead* or copper* or shall be lined with other durable and watertight materials. All lining materials shall be pitched one-quarter (1/4) inch per foot (20.9 mm/m) to weep holes in the subdrain of a smooth and solidly formed sub-base. All such lining materials shall extend upward on the rough jambs of the shower opening to a point no less than three (3) inches (76 mm) above the top of the finished dam or threshold and shall extend outward over the top of the rough threshold and be turned over and fastened on the outside face of both the rough threshold and the jambs. Non-metallic shower sub-pans or linings may be built-up on the job site of not less than three (3) layers of standard grade fifteen (15) pound (6.8 kg) asphalt impregnated roofing felt. The bottom layer shall be fitted to the formed sub-base and each succeeding layer thoroughly hot mopped to that below. All corners shall be carefully fitted and shall be made strong and watertight by folding or lapping, and each corner shall be reinforced with suitable webbing hot-mopped in place. All folds, laps, and reinforcing webbing shall extend at least four (4) inches (102 mm) in all directions from the corner and all webbing shall be of approved type and mesh, producing a tensile strength of not less than fifty (50) psi (344.5 kPa) in either direction. Non-metallic shower sub-pans or linings may also consist of multi-layers of other approved equivalent materials suitably reinforced and carefully fitted in place on the job site as elsewhere required in this section. If you want to go with the Kerdi/ Hydroban hybrid, Laticrete WILL warranty it, so long as you follow their spec. Email me, and I';ll send it to you (for some reason, I can't upload it to Photobucket, and therefore can't post it here). Here is a link that might be useful: Harry Dunbar's Showerpan tutorial

So as I understand Greendesigns suggestion: use a 3cm slab and lay it at a slant to one side, using a trench drain at the end of the slope. The build up for this slope would be made under the slab, instead of removing material from the slab, to get the 1/4" slope needed to drain H2O. I think that sounds doable. What would one use to build up the slope? I wonder if you could joined 2 or more slab remnant pieces together (to keep the price down) to get you shower pan size that you want. I bought remnants at a local stone yard for a potential bathroom remodel in the near future. I am so happy that I got these pieces! I got them for $5/sf. It may have been under priced but the yard went with the quote anyway. They ended up adding an extra piece to the pile that I hadn't planned on but was so happy to get. I got 29sf for $150. The reason I am interested is that we too put in our own soapstone kitchen counters. I had my husband do the heavy lifting but I did the cutting, scribing, shaping and sanding. I loved doing this work.

The 'premium', as they call it, is a better material with more choices in size and color. The pan is treated as any other pan/base with the tiled walls coming down over the edges. I'm having the walls tiled, just don't want tile on the floor. The preformed bases are made with a slope and a drain location of the end, center or a grate-type drain along one end. Here is an example.