It is now occurring to me that I might be best off if I don't try to build up a pony wall and instead add whatever bracketing and bracing required to adequately support the "floating" countertop from the back wall. I am guessing that will involve opening the wall to reinforce the studs, and I am not sure if the entire slab (3/4 inch limestone) can even be supported from the back wall.... From 00-Temp

Base cabinets were mentioned once. They would be good bracing! It seems the discussion went towards braces that you buy in a store. To attach base cabinets as bracing one will need angle iron, and a lot of fine tuning work in terms of the cabinet feet and height above the floor. Uh-oh. Sounds impractical now. So, the 90 degree braces at floor level now seem to be the best thing to do. mudworm, on lowes.com I entered two keywords: aluminum tube. I got positive results. Here are some of them. Item #: 215640 Item #: 216100. Go to wherever they have these in the store and you will see steel tube too. Or, web search for steel tube. I just figured that "aluminum tube" would be easier to search for. Buy aluminum tube if there is no steel. Once a metal is made into a tube it is very rigid. In home depot I have also seen steel and aluminum tube. So, tube IS available if you know where to get it. Tube is stronger than thin flat metal. If you add tube on top of the braces you will have both the benefits of what advertguy proposes and the benefits of the 90 degree bracing, and no deleterious secondary impact. advertguy in your latest post "Remove those braces from the bottom" is not clear. Hth

I know that this comment is LATE, but maybe it will help someone…. I don’t know how they did it, but I recently assisted with a Holiday Homes Tour. One of the houses that we used for this event (thanks to the builder’s generosity) had EXACTLY the kind of wall you described in the primary bathroom and it was BEAUTIFUL…. I so wish that I had thought to do this during my homes construction…. I DETEST the 4-foot high pony wall in our shower and the view of the shower’s interior every time I walk into the bathroom…. I certainly hope that you were able to implement your vision for that space. ❤️

Besides the fact my shower curb was pooling water, the shower floor was also pooling water, it is not pitched correctly. I called my tiler, he agreed to tearing out the bottom row of the tiles to fix the pitch and rebuild a new shower curb without metal trims, he will mitre the corner edges. I told him I would like to have a flood test, he agreed to that as well. I asked him if he can extend the shower pan liner to cover the entire curb, he said no, I also asked if he will apply RedGard over the shower floor and curb before he tiles, he said no. My dilemma is whether to let him fix the shower pitch and curb without waterproofing with RedGard? Is that step important? Or shall I hire another tiler that would install a shower the way I want . Thank you in advance for any advice you can give me, Irene