I'm having a shower tiled and I noticed that the tiler didn't put thinset over the entire area, just on the back of individual tiles.
The tiles are heavy stone 3/8x6x12. He used a 1/2 x 1/2 trowel to apply the thinset. It looks like he put just enough in the middle of the back of the tile to keep it from smooshing out to the edges instead of applying it to the Durock® and pressing the tile into it.
Is this normal?