The membrain has a few reasons for being...

Its a vapor barrior (concreats allways outgassing, it doesnt dry to my knowlage)
and, concrete expands and contracts at different rates then ceramic tiles.

You say its in a rental, are you sure there wasnt another reason for the tiles being moved?



I'm using some construction adhesive to resecure a few tiles in our bathroom... buying time for the remodeling (like summer after next type of deal)
I'll let you know how that works out

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95 Honda Shadow ACE 1100.
1999 Plymouth Neon Expresso. 2.4 swap, 10.5 to 1 comp, big cams. Autocross time attack vehicle!
2012 Escape, 'hunter" (5 sp 4cyl)