It provides a smooth uniform surface to work with.
Backer board over sheet vinyl.
Most vinyl tile floors are thin enough to support the extra thickness of both the backer board and the tile.
Then put down mortar with a 1 4 tool onto the ply floor boards.
If the vinyl was applied over a wood subfloor you should install 1 2 thick cement backer board on top of it first using corrosion resistant screws driven into the floor joists.
Here s how to go about tiling a floor over vinyl flooring.
I would avoid doing this if i were you.
However if you can t remove the old surface or otherwise decide to install over it lay a backer board with thin set over the old surface to serve as your new subfloor material.
In very good condition there is one small squeek in the floor between the shower and the toilet that i want to eliminate with the extra cement board.
To smooth the floor i covered screw heads and seams in the cement fiber board with thinset.
Installing ceramic tile over vinyl or linoleum surfaces can be more complicated than expected and probably should be avoided whenever possible.
In my opinion vinyl tiles are out as well due to the fact that the thinset bond is only as good as the bond of the surface under it and i ve seen vinyl tiles especially peel and stick let go way too easily.
1 4 luan plywood is common for use underneath vinyl flooring.
Cement backer board is for use under tile.
Another option to backer board on wood floors is one of the new polyethylene membranes such as schluter ditra.
The tile used on this.
The floor is now smooth.
This is a 17 year old home.
I have not seen anyone try to put vinyl over it.
Here is my concern.
First changes in humidity make solid wood shrink swell and cup more than plywood.
If thickness is an issue however 1 4 inch thick backer board can be safely installed.
I have since decided to install vinyl sheet flooring.
Second the strength of wood boards isn t always consistent.
The biggest danger in doing a tile installation over vct or sheet vinyl flooring is not knowing what s under that flooring.
According to backer board manufacturers and tile setters installing backer board directly over an old solid wood subfloor is risky for a couple of reasons.
The second problem with tiling over vinyl is the underlayments used for vinyl installation.
When tiling over existing vinyl flooring on a plywood subfloor it s not necessary remove the vinyl flooring as long as you apply a layer of cement backer board first to provide a stable surface for the tile.
The same is also true for sheet vinyl.
Installing over existing vinyl.