Ask a Pro
Ask a Pro: Bathroom floor fix
The vinyl tiles on my bathroom floor were laid over existing tile, which caused the top layer of tiles to shift. I have removed all the tiles down to the concrete, but now the floor is too uneven to lay a solid piece of linoleum over. I am thinking of laying down plywood, but it would have to be glued down. How will this change affect replacing the toilet? - Mark, via email
You did the right thing by going right down to the concrete and starting over. Make sure you use a heavy, metal floor scraper (sold at most home-improvement stores) to make light work of most deposits on concrete. Think of it as a 6″- to 8″-wide chisel on a shovel handle. If the deposits are really tough, you can also rent a mechanical scraper from an equipment rental shop.
Clean the floor as well as possible, then treat it with a concrete-bonding agent and pour out a thin layer of self-levelling concrete. This process sounds much harder than it actually is but both the concrete and the bonding agent are available at home-improvement stores.
Finally, if you must go to a layer atop the concrete, stay away from plywood. Cement board or HardieBacker board is the way to go, as these materials are far more moisture-resistant. To attach the board to the concrete floor, use either thin-set mortar or a polyurethane adhesive.
As an alternative, consider installing inexpensive ceramic tile and eliminate all the hassles associated with the linoleum tiles. Ceramic is actually a do-it-yourself-friendly project and requires very little in the way of tools. For the minimal cost increase with ceramic, you gain a floor that both looks and wears better than peel-and-stick tiles. Also, you will have some new tools and a new skill that will follow you to your next home.
As for the toilet, unless you raise the floor by a huge amount, a new wax gasket should suffice. If a new gasket isn’t thick enough, you can get a thicker one for situations such as these, or you can simply stack two gaskets together.