How to Clean Tile Grout

Illustration of products to use (and not use) when cleaning grout

 © The Spruce, 2018 

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.

What You Need

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.

Supplies

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

How to Clean Tile Grout With an Alkaline Cleaner

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.

  1. Mix the cleaner with water, as directed by the product label.
  2. Apply the cleaner liberally to the grout lines, and let it sit for a few minutes.
  3. Use the grout brush to scrub vigorously at the grout lines, until stains are gone.
  4. Sponge up excess cleaning solution.
  5. Rinse with clear water, and sponge up the water.
  6. Use a towel to dry the tile completely. Let the tile air-dry overnight before resealing the grout.

Cleaning Tile Grout With Oxygen Bleach

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. A more appropriate product is Ajax Oxygen Bleach Cleaner or a similar product.

  1. Mix the powdered bleach with water to form a paste.
  2. Apply the paste to the grout, using a sponge. Let the paste sit on the grout for 5 to 10 minutes.
  3. Scrub the grout lines with a stiff grout brush.
  4. Rinse with clear water, then wipe the tile down with a clean cloth. Let the tile air-dry overnight before resealing the grout.

Cleaning With Chlorine Bleach

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. 

  1. Wear safety glasses and rubber gloves, and wear old clothes. Bleach is caustic to skin and can bleed the color out of clothing.
  2. Open windows and ventilate the area. Bleach is toxic and releases noxious fumes.
  3. Dip the grout brush into the pure bleach, apply it to the grout lines, and scrub vigorously to remove stains.
  4. Rinse thoroughly with clear water.
  5. Dry the tile surface with a clean, dry towel. Let the tile air-dry overnight before resealing the grout lines.

Avoid Vinegar or Baking Soda

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 has very little effect as a cleanser on dirty grout.

Sealing the Grout Lines

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.