Few finishes can rival the beauty and lasting quality of a ceramic tile floor. This high-quality product, professionally installed can, with periodic maintenance, last indefinitely.

When such a floor does need care, it usually is because the grout surrounding the individual tiles is stained, cracked or flaking. Grout is the mortar-like material that gives the finished product a monolithic appearance.

Repairing a cracked or chipped piece of ceramic tile is the other most common repair. This is a bit more complicated, but can be accomplished with proper tools and materials. Before attempting a repair, investigate what is causing the damage. Otherwise you might complete the repair only to be back in the same boat soon thereafter.

Cracked grout and/or tile usually are the result of a flexing floor. Although this condition most often occurs when the floor is wood with a crawlspace or basement below, it also can occur over slab concrete construction.

Over-spanned floor framing, poor or nonexistent framing support, thin subfloor material and lack of a stiffening layer are the most common causes of cracked tile. A means of "stiffening" a floor to prevent it from flexing is to strengthen the floor framing by installing "sistering" floor joist to existing floor joist. Installing blocking perpendicular to and between existing floor joist is another method.

If the floor framing is solid and the subfloor substantial, the culprit might be a gap between the underpinning "support" posts and the concrete piers. Often, these posts will dry and shrink, or the piers will sink, creating a gap. This can be remedied by installing shims into the gap or removing the short posts and replacing them with ones that fit snugly.

To avoid cracked tile on a concrete slab, divert water surrounding the house AWAY from the house. The soil surrounding the house should be graded away from the foundation. Gutters should be installed to catch rainwater shed by the roof. This water should be transferred by downspouts that discharge it into a drainage pipe and a municipal storm drain or other water-collection system.

With a concrete slab, cracks in tile normally result from movement of the slab, expansion and contraction due to changes in the soil condition below the slab. Excess water can cause water pressure that pushes upward on the slab from below, causing a hairline crack in the tile and/or grout.

With these precautions taken, you're ready to repair your cracked tile. The tools needed are safety goggles, hammer, cold chisel, electric drill with a carbide tip bit, grout saw, putty knife, grooved trowel, rubber grout float, small block of wood, sponge and clean white rags. Mastic adhesive, replacement tile and grout are the materials needed.

The first step is to remove the damaged tile. Use a grout saw (a device about the size of a toothbrush) to remove the top layer of grout surrounding the tile being replaced. Next, drill a series of holes using the drill and carbide bit. This will make the tile easier to break up without disturbing any surrounding tiles. Put on safety goggles before using the cold chisel and hammer to remove the tile.

Use the cold chisel and a putty knife to remove any remaining adhesive. This will create a smooth surface for the replacement tile.

The new tile now is ready for installation. Using the grooved trowel, apply an even layer of mastic to its back surface. Set it into place being sure that that the joint surrounding the tile is uniform at all sides. Plastic spacers can be used for this. Using a wood block covered with carpet, gently tap with a hammer to level the replacement piece with the surrounding tiles.

Once the tile has set up overnight, the grout can be installed. It comes in powder form for on-site mixing, or premixed. Also, it is available sanded and unsanded. The former offers greater structure integrity and should be used on joints that are wider than 3/16 of an inch.

When mixed, the grout should be of a pasty consistency. Apply it with a rubber grout float. The grout should be forced into the joints in a diagonal direction. The float should be held at about a 30-degree angle from the tile surface. Excess should be wiped off with a damp sponge and cool water.

After the grout has dried, a haze will be present on the tile. This can be removed by polishing it with a piece of cheesecloth or rag. Allow the grout to cure for a couple of weeks and seal both the tile and grout with a high-quality silicone-based tile-and-grout sealer. This will make the installation more water-resistant and prevent the grout from staining as easily.

The biggest challenge is finding tile to match. If none is available, consider removing several pieces of tile at random and replacing them with contrasting ones. Your repair, thus, could become a work of art.