I have read through a few threads about this topic on here and although I understand that in general it isn't a good idea to do this I wanted to ask about a specific situation.
I have a neighbor who about 8 years ago laid porcelain tile over his existing wooden deck. He told me that he simply used liquid nails to adhere the tile to the deck and did NOT grout in-between the tiles, just put them down flush with each other. The tiny gap in-between the tiles allows rainwater to escape down and then I assume it drips between the old deck boards. Like I said, he has had it this way for 8 years with no major issues.
This sounds to easy/good to be true but is the proof in the pudding?