Can you lay ceramic tile over a vinyl floor? If so what's the process?:D

I certainly wouldn't. You DO NOT know what the sub-floor construction is. If you insist upon doing this (without knowing subfloor) install 1/4" hard-backer, nailed/screwed every 6". CAUTION; when cutting hardi-backer, wear a good mask. If you do not use the hardi-backer, scribe the vinyl, but there is no guarantees this will be a good installation as the vinyl may not be glued securely... many,many problems can arise from your suggested process.

I Will Agree With Pergammano, I Also Wouldn't Advise This Method , However Ive Seen It Done Before, And Ive Also Done It. First Makes Sure You Get Out All The Squiks Out Of The Floor, Second You'll Need To Sand You Floor To Get Rid Of The Gloss That's On There, Just A Little Sanding To Get The Shine Off Lets Say. After This You Can Lay The Tile, Use Thinset Mortar, 1/4 Trial,
Now As Far As How The Floor Has Been Laid , If The Viynl Was A Perimater Glue, Which Is Just On The Edges, Id Say Not To Do This At All. Use Backer Board, If The Floor Was Glued All The Way, You'll Probably Be Fine, Do Keep End Mind Is You Do Have Problems There Will Be No Warranty On The Floor Just Because Of The Installation Process. So Its All On You.
Here's My Experience With This, I Did This In My Own House Just To See How It Would Work, Its Been Down For Over 5yrs, With No Problems , No Cracks Joints, No Broke Tile.this Is In 2 Baths,
So My Advise Is Not To Do This For A Customer Or A Friend, Lol, If Its Your Home Try It And If It Doesn't Work Its Only You That Mad.
Good Luck

Okay, my concern is that I don't know if the vinyl flooring in my bathroom has any asbestos content. My home inspector indicated that it is highly unlikely, but of course he could not guarantee this. So the suggestion was just to cover the floor. There arer several areas of the floor that were previously broken off and there are parts that seem to be slowly coming up on it's own. My next question would be what's the easiest way to remove both the glue and vinyl flooring before laying the hardi backer board.

I noticed that several people have indicated that you can identify some asbestos tiles by their size. Were the tile with asbestos only made in certain sizes? My house was built in 1954. The bathrooms and kitches have the original full sheet vinyl flooring on them. Would this mean that the tile did not have asbestos in it?

Lets Scratch The Tile Over Viynl Floor. I Didn't Know Your House Was That Old, Your Floor Most Likely Has A lot Of Sqeaks, And Humps In The Floor.
It Would Just Cause Cracks And Broke Tile.
So You'll Have To Lay Backer Board Down, And Go With 1/2, This Will Help With Movement Of The Subfloor. As For Pulling Up The Viynl, Id Just Leave It. If You Don't Know If It Has Asbestos In It.leave It Alone, If You Call An Asbestos Company To Remove It. Your Talking A lot Of Money, The Way Asbesos Hurts You Is By Breathing It In, So No Sanding, Scraping, Or Chiseling Of Any Kind. No Sawing Either.

Actually, all you need to do is, find the floor joists, and screw the old vinyl and underlay down every 6 inches on each joist to secure the old underlayment down as if it were subfloor. This is so you do not disturb any asbestos by tearing out the old, and anchoring down securely solid. You should make sure there is no squeeks in this process. Now just underlay,preferbly with hardybacker, and if your floor is pretty well level, go with quarter inch. Make sure to use the hardybacker screws since you are going through vinyl. If no vinyl you could nail down with ring shank nails. This method should be all it takes and should hold up fine for this project.

No reason to sand or scribe the vinyl. If you are sanding or scribing the floor, you might as well pull it up. The finish on the vinyl will not effect the hardybacker in any way. That is like saying that putting a slip sheet for a mud bed will effect your shower floor. Just anchor down the vinyl and underlayment through the subfloor, into the floor joists, every six inches until solid, and underlay and lay.