Secure your wainscoting in place with masonry screws and a drill equipped with a carbide tipped drill bit.
How to wainscot over tile walls.
Take wall hangings and mirrors into consideration.
Drill through the grout lines and attach the strips to the studs in the wall using screws.
Install your wainscot paneling.
Choose the proper screw length based on the thickness of your tile and the wainscoting panels.
Affix the beadboard panel over the tile wall placing it against the wall so it rests on top of the baseboard molding and then straighten it so it lays flat on the wall.
Cut the 1 2 inch plywood into 2 inch strips and apply the strips over the tile.
Cut the first piece of beadboard to fit the wall if needed or leave it whole.
But only if it is high enough.
If your wainscot is tile then it can serve a dual purpose by working as the backsplash behind your sink.
The masonry screws must pass through the wainscoting and the tile and penetrate the wall by at least 1 2 inch.
Apply construction adhesive to the back of each piece as you stick them on the wall on top of the existing tile up to your level line.
Press firmly against the panel all over the surface to help the adhesive make proper contact with the tile.