Q. I have a client who had a tile floor put down a few years ago. The tile installer told her the grout already had a sealer in it so no additional sealer was ever put on. Now the grout is stained, and she has been trying to clean it with bleach (the grout is white) but cannot stand the fumes. Is there anything that can be used to clean the grout that would be fairly simple to use and not smell too bad?

A.Tilesetter and author Michael Byrne responds: No grout I ever used or heard of contained a built-in sealer, and although latex and epoxy grouts are somewhat more stain resistant than regular Portland cement grouts, a quality high-performance sealer should always be applied — after the grout has cured — to help reduce staining and to make housekeeping easier.

White grout is never the best choice for any tile installation intended for a heavy-use or food service area, and without a sealer, it may turn "antique" white or even gray. Bleach can sometimes be used to remove stains from white grout, but it will fade colored grout. Once grout has been cleaned, it should be allowed to dry thoroughly, then be protected with an appropriate sealer.

The first step in the cleaning process is to identify the grout. Many grout manufacturers offer lines of cleaning and sealing products that, when used as a single-source system, can significantly reduce fading and color change. If an after-market sealer is used, I choose a manufacturer that produces both a sealer and a cleaning preparation. Some acid-based cleaners may require one or more wash-rinse neutralizing cycles before a sealer can be applied.

On new installations, I never use regular grout, which is a mixture of Portland cement, sand, and water. Instead, I replace the water with a liquid latex or acrylic, and mix it with regular grout powders (sanded or unsanded). If the latex component is factory-added as a dried powder — called polymer-modified grout — water is the usual liquid component.

After the tiles are cleaned, and once the fresh grout joints have begun to set up, I strike the joints to produce a smoother grout surface. When hard, cured, and protected with an impregnating sealer, smooth-surface joints are significantly easier to clean than joints whose surfaces are rough or uneven. Striking fresh grout is one of the secrets of easy maintenance for tile. Adding the protection of a quality sealer makes this kind of finish ideal for an installation whose appearance is important.