Thanks to a fortuitous comment in a tile store, I've learned natural stone is a bad idea in a steam shower. We had picked out limestone for the floor in our bathroom and shower. We've now chosen an appropriate tile for the floor of our shower, but we want to keep the limestone on the rest of the bathroom floor. It's a curbless shower btw. If we do stick with the limestone, should we take any precautions with the limestone tile that will run along the edge of the shower?