Tile Caulk Cleaning and Whitening

person with a pink glove pointing toward the mildew along the caulk around the bathtub
  • 2-4 hours
  • Beginner
  • 0-80
What You'll Need
Household bleach or bleach pen (grout and caulk repair pens)
Old toothbrush
Baking soda or white vinegar
Bowl or bucket
Rubber gloves

Tile caulk is a rubbery material that is used to line the area between tiles and the edges of a bath or sink. Due to its frequent contact with water, the caulk can become moldy and discolored, giving your bathroom an unpleasant and dirty look.

Depending on the level of dirt and mildew on the tile caulk, you may be able to make it white again by following the process outlined below.

Step 1 - Assess the Situation

To determine whether the stains and discoloration on the caulk can be successfully removed by the following methods, you need to work out whether mildew is on the caulk or beneath it. If the mildew appears to be beneath the caulk then you will need to remove it and replace it. If the stains are on the caulk, then simple cleaning should get rid of them.

Step 2 - Try Baking Soda or Vinegar

a bowl of baking soda and jar of vinegar with other supplies

Applying either a baking soda/water paste or vinegar/water solution is a gentle, natural way to start. Scrub your preferred mixture into the stains with a toothbrush. Let the caulk dry before moving on to the next step. Despite some popular but misguided advice, you shouldn't mix the baking soda and vinegar together. Their chemical structures will largely cancel out, and the resulting substance will be salty water.

Step 3 - Use Bleach

Applying a bleach solution to the caulk should help whiten the surface (though it won't necessarily kill mold or mildew, so if you suspect those are present, reach for a more standard bathroom cleaner). Put on your rubber gloves to protect your hands before mixing ¼ cup of bleach with 1 gallon of water. Remember to open the bathroom window or switch on an extractor fan to help aid ventilation. This is necessary to prevent the inhalation of toxic fumes. You should also use eyewear to protect you in the case of splashing bleach. Apply the bleach and water solution to the caulk generously, using a sponge. Leave the solution on the caulk for around 10 minutes for the maximum effect.

Step 4 - Scrub

Scrub stubborn stains off of the caulk with an old toothbrush. Try to do this gently or you might actually scrub the caulk off. Rinse the bleach and water solution off the caulk with warm water. If you're not happy with the results, try repeating the above process.

Step 5 - Use Bleach Pens

Bleach pens or grout and caulk repair pens are another option. They're easy to get hold of and provide a fuss-free solution. Simply press the pen along the caulk, leave it for 10 minutes to set in, and rinse with warm, clean water. Repeat as necessary and let the caulk dry naturally before allowing the area to get wet again.

Step 6 - Protect Against Further Staining

hand holding a tube of mold-free caulking

The correct application of caulk and using a mildew-resistant caulk during initial installation are the best methods in the prevention of mildew growth. However, adopting the following methods is also advisable to reduce the presence of this problem in your bathroom.

Clean the caulk regularly with a mold and mildew remover spray to stop the spread of mildew spores. Turn on the extractor fan or open a window whilst using the bathroom. Ventilation will reduce the humidity in your bathroom. Once you are finished showering or bathing, dry your tiles with a towel or cloth so that mold and mildew will have less moisture to thrive on.