Hard tiles are deceptively fragile. Virtually any kind of tile you can lay, ceramic, porcelain, brick or stone, can crack or come loose if it's not set on a proper underlayment. This is because tile, unlike wood flooring, has no "give'' that allows it to move with its surroundings; if it moves, it will crack. So it's important to have an underlayment that is rock-solid, and also free of moisture, which can cause the mortar that holds the tiles in place to come loose.
Concrete
A concrete ground floor on slab construction is a good underlayment for tile, provided the concrete is solid, free of cracks and is properly sealed against moisture. If it's not properly sealed, moisture will rise from below and cause the tiles to come loose. To determine whether your slab is properly sealed, cut out a 2-foot square of thick plastic tarp and tape it down over the concrete with duct tape, sealing the edges completely. Let it sit for 24 hours. If the underside of the plastic remains dry, you're good to go; if moisture condenses on the plastic, consult your home improvement store about the proper materials and methods to seal the concrete.
Cement Board
Cement board, a harder, stronger, cement-based version of drywall, is the preferred underlayment for most tile applications over wood or vinyl floors today. Half-inch-thick cement board can be cut like drywall; scored and snapped. It's laid on the surface with carpenter's glue or mortar, then secured with drywall screws every foot or so. The seams are then filled with mortar, which is smoothed out with a flat trowel. The big advantage of cement board is that it can give almost any surface the stability of concrete.
Membrane
Sometimes cement board isn't a practical choice because of how much it raises the level of the floor. If you have a plywood underlayment already in place, which is typical in many newer-construction homes, it is possible to lay tile over it without cement board. The plywood should be very solid and free any splintering or rot. It's a good idea to cover the plywood with a tiling membrane, which is a 1/8-inch thick roll of construction-grade backing that is secured to the plywood with thinset mortar to provide a stronger tiling surface and moisture resistance. Once once membrane is set, more mortar is spread on top of it to set the tiles.
Related posts
Vinyl tile comes in many different patterns and colors.Vinyl tile can serve as a long-lasting means to cover a floor quickly and easily, using simple tools. The subfloor for vinyl tile, especially...
Sheetrock, or drywall, is commonly used as a backer board for ceramic tile installations. According to the Gypsum Association, green board, a drywall made with a green paper, is specifically desig...
Score the lines you want to cut with a utility knife.Installing floor tile requires a strong, flat, stable surface that can support the tile and the adhesive holding it in place. Unless you have a...
Durock helps ensure a long lasting tile floor.Tile applied directly to a plywood substrate is prone to cracking, due to natural movement in the wood as a result of settling and changes in humidity...
When you tile a floor, the first issue you need to consider is what kind of subflooring to use. In some cases, you can lay your tile over an existing wood floor or over a plywood subfloor, but if...
