I am planning on putting down laminate flooring on a 3/4" plywood original subfloor where there is carpeting now. I also want to put the same laminate flooring where it leads into the kitchen area from the above area, but there is already a luan subflooring over the 3/4' original subfloor,that has 12'X12' stick down tile floor tiling. Do I need to rip up the luan underneath the tile flooring??? Or is there a way to transition this area without a trim piece that will no doubt get kicked on due to the differing heights????
Guessing that the luan subflooring is only 1/4" thick I would strongly suggest that you remove it. Since the existing carpet squares are glued down to it I suspect it would be way more work trying to remove all the glue and prep its surface to a suitable condition for the laminate flooring.
If you tried to leave the luan subflooring any type of transition that you attempted to use would most likely be noticable to some people to say the least. In addition the transion zone would place stress on the snap together joints of the flooring causing them to not stay nicely closed.
I am not a big fan of laminate flooring in the first place but suggest that it wants to be laid down on a surface that is flat and continuous.