Replies

1. 
   mikemahan3 | Aug 31, 2021 01:27pm | #1

   I have never seen tile like that. I have to wonder why it isn't symmetrical. That being said, I would never fill the back with thinset. Thinset shrinks a lot. That much on the back of these tiles would probably crack them. If I were using these tiles for a backsplash I would probably not use thinset at all, but a bead of adhesive around the outside.

2. 
   greg_e | Aug 31, 2021 02:17pm | #2

   I've never seen a tile like that before. Maybe fill the back with non shrink grout prior to installing normally?

3. 
   sawdust_steve | Aug 31, 2021 02:38pm | #3

   Contact the supplier or manufacturer and ask for their specifications

1. 
   user-7877086 | Sep 01, 2021 02:47pm | #4

   First thing that I did..., waiting for their reply.

4. 
   florida | Sep 01, 2021 02:57pm | #5

   https://www.johnbridge.com/vbulletin/showthread.php?t=121258

   Third answer down

5. 
   tfarwell | Sep 10, 2021 07:14pm | #6

   What the ??? I'd flush the backs up with mortar, let it set up, then set them like normal tile.

   There's a small evil part of me that wanted to suggest spray foam :).

   Best of luck to you.

6. 
   user-7786918 | Sep 11, 2021 07:45pm | #7

   I'm nearly certain the pictured tile is tile baseboard. Not designed to be installed as wall tile with tile stacked above it. The reason for the recess is so that thin-set mortar can bond the tile to the substrate without creating a large grout joint along the top edge of the tile. So the tiles can be set tight to the wall. Thin-set, when properly mixed does not shrink a lot as described above. Use a notched trowel and test set a tile to the substrate, then remove the tile to see what type of transfer you get. Increase the notch size if not enough thin-set is bonding to the back inset part of the tile. One way to know for sure if this is indeed tile base is if the top edge of the tile is glazed. If it's glazed it is meant to be exposed.