Tile experts - Help, please! Niche with marble shelf
My bathroom reno is progressing more slowly than I would like, but that gives me time to do more research on the logistics of installing a marble shelf in the planned shower niche. My inspiration is stacyneill's tall niche on the plumbing wall in her daughter's bathroom, most recently interpreted by kercove. My tub/shower surround is 3x6 subway field tile, and the niche will be 12" wide by 18" tall. My plan is to use marble tile cut to depth for a shelf 6" up from the bottom, and then have a 12" recess just above. My GC's tile guy picked up a Noble niche, the kind with two separate compartments, and a 12" finished interior width. When I asked why, I was told that he was concerned that the tile lining the single cavity box wouldn't be strong enough to hold the weight of the 3/8" marble tile cut to size. I can understand that a 12" wide tile in a 12" wide niche might not be held up by more than the thickness of the subway that will be applied to the side depth, but then I see all the beautiful niches here and wonder how it's done. Are these all made from scratch, or can the single cavity Noble be made to work? I really would like the clean, unbroken look of the field tiles without a row where some of them will have to be trimmed down to accommodate the 2" partition divider on the 2-part niche. I would really appreciate your insights; thanks in advance!