How to Clean Tile Grout

Whether it's floor tile or wall tile that's dirty with grease, soap scum, mold, or just plain dirt, cleaning grout requires two things: a grout brush and a suitable cleaner. A grout brush is a small, stiff-bristle nylon brush, available in handheld and long-handled sizes. You can substitute a toothbrush in a pinch, but its bristles are too soft to do much good. As for the cleaner, a lot of formulas work, so you can try different options to find the best performer for your tile. While there are commercial grout cleaners available, it is just as easy to do this with ingredients you already have on hand.

Tile grout should be cleaned whenever it becomes dirty or discolored with mold and mildew, but the frequency will depend on where the tile is located and how heavily the surface is used. Tiled wall surfaces may require this only infrequently, while tiled shower walls subject to lots of moisture and constantly humid conditions might require it weekly. The best rule of thumb: Scrub the tile grout whenever it is obviously discolored or dirty.

It is best to try grout cleaners in the order of harshness, beginning with an alkaline cleaner, then proceeding to oxygen bleach, then chlorine bleach, as necessary.

• Grout brush
• Chlorine bleach
• Oxygen bleach
• Alkaline cleaner
• Safety glasses
• Rubber gloves
• Towel

The Tile Council of America (TCA) recommends alkaline cleaners for removing stains from grout. Alkaline cleaners include Spic n' Span, Super Washing Soda, and Mr. Clean, among many others. These cleaners are particularly good for cleaning dirty, greasy grout joints in the kitchen.

Unlike chlorine bleach, oxygen bleach is non-toxic and safe for the environment, and it doesn’t have a harsh chemical odor. It also doesn't stain colored grout lines. Hydrogen peroxide is a form of oxygen bleach; however, it is typically sold in diluted solutions, making it a relatively ineffective cleanser for tile grout. A more appropriate product is Ajax Oxygen Bleach Cleaner or a similar product.

One traditional way to clean grout lines is using household chlorine bleach. For a full-strength application, simply dip a grout brush into a small container of bleach, scrub the grout thoroughly, then rinse with water. There are also some great grout bleach products on the market. 

Alkaline cleaners are a better choice than vinegar or baking soda because grout contains cementitious mortar that can be dissolved by acidic cleaners, including vinegar. Don't use any vinegar or acid-based commercial cleaners on grout.

Vinegar and other acids are also a bad idea for stone tile because the acid can etch the stone. Another widely praised household cleaner, baking soda, is alkaline (not acid), but it is not very effective as a grout cleaner.

Cleaning grout lines can be a difficult and physical process. Once you have the grout looking clean and stain-free, sealing the grout will create a protective surface that helps prevent future staining and makes it much easier to keep grout clean. It's important to follow the manufacturer's instructions carefully when applying grout sealer. The tile must be clean and completely dry, and you must let the sealer cure fully before using the tiled area.