It will be fine.Continue with your project

If the existing vinyl is secure and in decent repair you can place the self-stick tiles directly to it. Just clean it well first.

Just a warining, the self-stick tiles tend to shrink very slightly over time creating gaps between tiles.

Everyone else pretty much answered your question pretty well but one thing I found that it will raise your floor about 1/8th of an inch. And for me that was enough so I couldn’t have a rug in front of my back door. Just keep your clearances in mind. Otherwise good luck.

There is No reason that you can’t go over the old vinyl with new stuff, EXCEPT, if the old floor covering is loose anywhere. If not, clean it real well and you’ll be proud of your new floor and your handiwork.

Believe it or not you should prime it, they (floor store) have a special primer to make sure they adhere to your existing floor tile, check it out, good luck Les the painter

As long as you lay the tiles properly, you will end up w/ a very professional looking floor….always measure and start in the middle, placing tiles outward in even distribution. And be sure to double check the pattern; the backside of each tile will have an arrow on the paper backing, keep all arrows pointing in the same direction. the tiles will stick to the old flooring extremely well, as long as you give that old floor one last very good cleaning w/ a non-residue solution.

Just as long as the old vinyl is thoroughly clean, your tiles can go down over the old floor. Need to use a good cleaner that will loosen up the old wax and dirt, and it will take some of the sheen off of the old floor. The tiles will stick well then.

sand it good ,clean it good ,it will work ok!!