Q: We plan to lay a new kitchen floor in our lake house. We purchased peel-and-stick tile, hoping we can lay them right over the existing vinyl tile. How should we prep the floor before installing?
A: Although it’s possible to lay vinyl tile directly over some existing floors, such as wood and sheet vinyl, we strongly encourage you to first put down a new plywood underlayment. Plywood is the best way to ensure the tiles will bond tightly and that the old floor won’t telegraph through the new tiles. Apply a thin layer of leveling compound along the plywood seams, and then allow it to dry and sand the seams smooth before laying the tiles. If you insist on installing directly over the old floor, first mop the floor to remove all dirt and debris, and then use ammonia and water to remove the wax coating on the old tile. Trying to stick the tiles to wax won’t work; the tiles will just flake off. When installing, butt the tiles closely together for very tight seams, and butt them to the edges of the walls, too. Peel-and-stick tiles can sometimes slide out of place, revealing wide gaps at the seams—butting them tightly will minimize this.