QUESTIONcan i install tile over linoleum with thinset ?. dont want to use backerboard . dont want to raise height of floor if i can avoid it. have seen membranes to use but some info says to just rough up linoleum and use thinset. whats is the best way. thanks in advance.
ANSWERANSWER - As long as the linoleum is well attached to its substrate, and the substrate is structurally sound, then you can install tile over it. The new tile installation will only be as good as to what it is attached to.
First make sure you don't have excessive deflection in the floor. If you can see or feel it move up and down then it is too much. Standards say not to exceed L/360 where L equals the length of the area you are measuring.
The linoleum is probably contaminated with wax or whatever. As long as it doesn't contain asbestos you can roughen up the surface to remove any contaminates and to allow the adhesive to bond to it better. Clean it thoroughly.
You can use a polymer thin-set mortar that the manufacturer recommends for the application. They are normally more flexible mortars. Check any of the major manufacturers products such as Laticrete, Mapei, Custom Building Products or any of the other manufacturers and follow their directions.