Historically, a thin gauged stone or porcelain would not be considered for many exterior applications, especially in wet and cold climates. If they were used, the installation would require multiple installation steps to address water penetration and collection, a heavy concrete slab for stability, mud-set or thin-set bonding and final grout and grout sealing. And if the installation was to be successful over time, regular grout maintenance and sealing was required to ensure zero moisture penetration. If invisible micro-cracks in grout lines did occur, future failure was assured. And unfortunately, a repair required complete removal and a reinstall.