Hi, this Kim Hauner from Interstyle. We manufacture a variety of glass tiles, and I hope to keep my answers generic so that it applies to any type of glass tile: 4×4 tiles are an excellent choice for the wall application. They are typically installed as individual pieces, rather than pre-mounted in sheets, making the job easy for the average installer. You are correct in asking questions about the structure, substrate, waterproofing and anti fracture membrane in preparation for the installation: Generally a standard 16″ on center stud spacing is considered adequate for most tile installations. Cement boards like USG Durock or Hardie Board and even Dens Shield from Georgia Pacific are all adequate substrates. We recommend an anti-fracture membrane under the glass tiles for a couple of important reasons: Glass, and in particular our clear glass products make it impossible to hide any type of crack. Glass is also very inflexible, so any bending due to movement of the substrate (shrinking, settling, etc.) may cause the glass to crack. Because of the higher cost of glass and the relative low cost and ease of installation of the membrane, we feel that it is cheap insurance. Membranes also act as a very effective water barrier as well as an acoustical barrier – neither of which can’t hurt. You can read about crack suppression membranes here: