The bath floor in my 1984 house is crumbling in high traffic areas. .
When I pull up the loose 2" tiles, the mortar bed is in 1" and smaller
chunks. It doesn't help that they laid the tile with the paper
backing still attached, not the best thing for sticking to cement.

I've been doing temporary patch repairs by cleaning off the backs of
the tiles, vacuuming up the dust, and re-laying them in wallboard
compound.

I guess I'm going to have to tear the whole mess out, put down a sheet
underlayment, and set the new tiles in mastic.. The hard part will
be getting the height set so they mate with the wall edge trim and the
toilet flange.

I don't understand what advantage bedding the tiles in mortar is
supposed to have, when the floor underneath is going to flex. I
suppose it might work on a slab, but not on wood.
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