I learned this the hard way many, many years ago. The tile and the wood frame move at a different rate during the heat cold cycles that occur every day. When that happens, the grout usually fails first. Once cracked it lets water seep under the tiles. If it freezes (sometimes that still happens), the water expands and pops the tiles loose and cracks them. Typically (hopefully) there is a membrane to stop the water from getting to the frame, but often there is not. Fortunately, the decks in these photos are not over living space, and they do have a membrane. But the tile will continue to fail rapidly.
But what about those railing posts top mounted to the deck? If they are screwed down, won’t those screws penetrate, and thus, compromise the membrane beneath the tile? Yes, they will. Now water can get to the frame.
For some time now, code requires that railings in this application are to be mounted to the vertical aspect of the deck assembly, the facia. When the railing posts are mounted to the facia, the deck the membrane is intact and way less likely to fail. The tile still will, but the membrane below will not.
Now if you’re looking at your exterior front entry and you have tile over a concrete slab, it should last quite a while, because the tile and its substrate move at much more similar rates when they cycle through heat and cold.
“But Greg! We want the look of tile over our wood frame deck we are building”. Call me and I will tell you another way to go about it…and it’s virtually maintenance-free!