If I Lay Porcelain Tile On Vinyl Flooring Is There Special Prep To Be Done To The Vinyl Floor?

I did this about a year ago on my dining room and kitchen  floors.  The most important aspect is whether or not your vinyl floor is well-adhered to it's base.  It should not be pulling up in any places but must be flat and well-adhered to it's base.  If there is any vinyl missing in spots then you'll have to fill those spots in.  The floor has to be level and in good condition.  The floor has to be clean, use a stripper if there is wax buildup.   I used a mastic glue and the tile went on beautifully.