Though more and more people are tiling right over their existing flooring, there are many disadvantages to this. Though you may think that this will save you time, tiling right over vinyl can compromise the stability and look of your ceramic tile. Here are the top three reasons not to tile directly over vinyl flooring.
1. It won't stick well.
The top layer of vinyl is similar to plastic and it is very difficult to adhere anything to it. Vinyl is shining with an artificial shine and as your base it isn't porous which means a good bond is very difficult to achieve. No matter what kind of glue you try to apply to the vinyl, your tiles will not bond well to the vinyl. There are some who recommend roughing up the surface of the vinyl for a better bond, but this really isn't an effective method.
Because the tile and vinyl will not adhere well to one another, there might be lifting after you lay the floor. If the vinyl begins lifting and pushing the tile up, you may have to replace a section or the entire floor. If you do tile directly over vinyl or linoleum flooring, you may find at a later date that you need to remove the new tile floor to get to the old vinyl because of lifting and instability. It is probably better to save yourself the time, money and hassle by removing it now.
It is important that your new tile floor is secure and stable and direct adhesion to vinyl flooring will not ensure that. There isn't a mortar on the market that will stick to the surface of vinyl at the level needed for tile installation.
2. It won't be level.
It is much more difficult to get the floor level if you tile right over vinyl. You won't be able to figure out the anchoring pattern when you tile on top of vinyl and this is one of the key factors in a stable and level floor surface. It will also be difficult when trying to insert transitions where the floor rises or where spaces must be filled. If you start with a fresh or existing sub-floor you will have a much more stable and level end result.
3. The sub-surface under the vinyl isn't suitable for tile.
Vinyl flooring is usually installed on 1/4" plywood or particleboard. These substrates are not approved for tile because of a different material make-up. If you lay tile right over vinyl or linoleum the safety of your floor will be compromised. Tile on top of a cushioned floor is very unstable and you can develop cracks in the tiles or the grout. Because vinyl flexes, it can crack the tile. It is nearly impossible to replace a tile with a chip or a crack once it is adhered so you may end up having to replace the entire floor in the future because of the vinyl lifting and flexing.
If you do want to leave your vinyl down, then you need to prepare the floor structurally for the tiling. You will need to screw down the old vinyl and then create a mortar base using mesh and concrete. If you don't want to get into pouring cement, you can lay down a plywood sub-floor. There are products on the market now that increase the crack resistance of tiles placed on wooden sub-floors. This method isn't really much different from lifting the vinyl up. It may seem like a lot of work right now, but taking your time and doing it properly now will save you a lot of time and money down the road.
If you are still determined to keep your vinyl down, then you might consider talking to a professional tile installer. They can go over all of the pros and cons with you and look at your specific situation.
Before you proceed with your plans to tile directly over vinyl flooring, keep all of this information in mind. Not only will you have difficulty with bonding and leveling, but you will also end up with a floor that is unstable and in some cases unsafe. This money-saving and timesaving route could end up costing you a lot in the future