Can Bleach Be Used on Caulking?

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Nothing ruins a good shower or bathtub quite like dirty, moldy caulk. The silicone and acrylic-based sealant is commonly used to seal gaps between tiles and around the edges of baths and showers in bathrooms as well as around windows, doors, and other areas of plumbing. It's usually white or pale in color, so over time, it is susceptible to discoloration from general dirt and mold. You don't need to remove and reapply caulking when it gets dirty. You may have wondered whether bleach can be used on caulking. The short answer is yes; bleach can be used to clean caulking.


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How to Clean Caulking With Bleach

To clean caulking with bleach, it's much more effective if you combine it with another ingredient: baking soda. To be clear, the baking soda doesn't actually do any of the cleaning in this case (although baking soda can be used to clean many other items at home). In this case, mixing bleach with baking soda turns it into a paste. Bleach by itself is quite runny, and you may have trouble applying it evenly enough to the dirty caulk. By mixing bleach with baking soda, you can achieve a paste consistency that you can then smear on the caulking with a brush.


As well as bleach and baking soda, you'll need:

  • A metal mixing bowl
  • A metal spoon
  • An old brush (such as a paintbrush or toothbrush)
  • Plastic wrap
  • A respirator


After putting on your respirator, mix the bleach and baking soda in the bowl with a metal spoon. Don't worry about exact quantities of each, as the goal is simply to create a thick paste. You can be generous with the baking soda since it's an inexpensive product.

Using the old brush, spread it on the dirty caulk. You can be generous with the mixture here too. Cover the treated areas with plastic wrap to prevent the bleach from evaporating too quickly. Leave it on for about an hour and then rinse it off with water. If the caulk is still dirty after an hour, you can repeat the process, although this technique of cleaning caulking is very effective, so this will probably not be necessary.


Alternate Your Cleaning Methods

While this is a great way of cleaning really dirty caulking, for regular maintenance of your caulked areas, it would be a good idea not to unleash the full bleach cleaning method every time. Bleach is a toxic substance, and repeated use of it on caulk could lead to damage. (Contrary to what some people think, however, bleach will not dissolve caulking.) Bleach is potentially hazardous to humans and the environment. Minimize your use of toxic chemicals when possible; ideally, alternate a deep clean using bleach with a milder vinegar and water cleaner.