Two questions: 1) I'm ready to grout the bathroom floor but do I extend the grout to the wall base or leave a gap for expansion? 2) Has anyone had any experience with interior use of Sierra Stone as a kitchen floor? (Please do not send me your poured concrete ads.. I can't use poured concrete for a couple of reasons and am ONLY interested in the Sierra Stone as a flooring option. ) Any input on this product would be greatly appreciated. Thanks! Lisa