Why does white caulking change color?

I suspect its mold...but this caulking is supposed to be mold/mildew resistant.

4 Answers

  • 1 decade ago
    Favorite Answer

    If the calking was "kitchen and bath" type it would be mold resistant. What molds is the soap scum the collects on the calking. The easiest was I have found to clean this is to soak a rag with chlorine bleach and place the rag on the mold. Leave it there for about half an hour and the mold will be gone.

  • 1 decade ago

    If it is changing color after it is applied, it could be air pollution sticking to the wet surface. cut a small piece out to see if it is a different color all the way thru. If it changed all the way thru, you have defective caulk. If it is only on the surface, it is air pollution. Try to apply caulk on a calm day so the caulk dries before the dust settles on the surface. If it is used inside, there may be mold allready started behind the wall, in which case you may have to remove some of the drywall to get at the mold growing inside.

  • 1 decade ago

    Another thing that discolors caulking is saliva. A lot of times a person will wet his/her finger with his/her mouth. I know one guy I worked for would never let a smoker do this as he said their saliva was the fastest to stain the caulk. I don't know if this is empirically true or not, but keep it in mind.

  • Anonymous
    1 decade ago


    if caulking was used in a bathroom yes your right.

    unless the caulk states its purpose.

    if you use outside caulk inside you can have mold too. check the product your using...


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