Looking for a quick answer.. I'm tiling my kitchen (approx 70 sq ft) with 12X24 porcelain tile over plywood. The person at the tile shop recommended i lay a metal mesh over the plywood to get a better adhesion to the tile. My question is pretty straight forward. is it necessary to use a metal mesh or is it sufficient to tile directly on the plywood? If yes to the mesh, what nails/ screws should I use? This is my first tiling job so any advise or recommendations is appreciated.