Why pop off a perfectly good substrate top layer unless it absolutely needs to be popped off? Consider the work involved. And a lightly sanded vinyl floor is as good a surface as plywood. So why not?
But I mainly side with methods that involve pulling off existing layers, despite the extra work or cost they bring on. When dealing with flooring you want to get it right the first time.
Issues and Potential ProblemsIssues you need to consider with the tile-over-vinyl method:
- Condition of Subfloor, Underlayment, or Even Joists: Pulling off a layer allows you to assess the condition of layers below. Are they in good condition? Is there rot? In rare cases, where the flooring is spongey tilted, or threatening to give way, you may even need to go all the way down to the joists to see what's going on (if joists are inaccessible via crawlspace).
- Type of Material in Underlayment: Equally important is the material used in the underlayment. Because the vinyl installation requires little more than a smooth surface, sometimes underlayment will be in the form of particle board or of lauan, a type of cheap, thin plywood. Neither are proper surfaces for laying your ceramic tile.
- Vinyl Installation Method: The vinyl flooring itself may not be installed in a manner that would allow ceramic tile to go on top. Mainly check to see if only the edges of the vinyl floor have been attached to the sub-floor. If the outside edges only are attached, with nails, adhesive, or staples, then you cannot tile over the vinyl. In fact, if your sheet vinyl is attached only at the perimeter, you're in luck. It's simple to pull off one of these edges-only sheet floors.
- Type of Vinyl Flooring: First, so we're clear on matters, we're discussing only sheet vinyl flooring, not tile vinyl. Because sheet vinyl is one, continuous piece, you stand a chance of being able to install ceramic tile on top without shifting. With vinyl tile flooring, the possibility of shifting is too great. Second, you cannot tile over a cushioned vinyl floor, even if it's sheet vinyl. These floors go under brand-names such as Armstrong CushionStep, Flexitec, or DuPont Elevations.
How to Install Ceramic Tile Over Sheet VinylIf you still want to do this, first check that the subfloor and underlayment total at least 1 1/4". Tile represents quite a bit of added dead weight, so you'll need a hefty substrate that will have minimum deflection.
If you have a lauan or particle board underlayment, then the tile-over-vinyl method is out of the running for you. Remove it. Replace with cement backerboard. Bond the cement board to the subfloor and screw into the joists. Tile over the cement board.
If you did not have to perform the previous step, lightly sand down the vinyl flooring with a disk sander. If the floor is small enough and you don't mind getting on your knees, you don't need to go out and rent a floor sander--use your power hand-sander. Thoroughly clean the tile. Apply tile to the vinyl with thinset.