Josh wrote:
Neither until you prep the floor properly...



That advice is as useful to me as tits on a boar hog, and is exactly
the kind of arrogant, snobby BS I hoped I wouldn't receive. Would it
kill you to perhaps elaborate as to HOW to prep the floor properly?

Well, you know the answer you're just trying to avoid doing it.

It's either take the old mastic off and smooth the floor down to a clean
surface or cover it w/ a suitable subflooring. One could try one of the
leveling compounds but it's likely more trouble over the entire surface
than simply taking the mastic off would be.

Whatever has to be flat and smooth as any imperfection will telegraph
through a thin tile.

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