How to Clean Mold on Rubber Sealant

Mold can form on many household and industrial rubber seals, gaskets, caulking and coatings, especially if they are exposed to damp or are not exposed to fresh air.

Common household bleach and hot tap water are the most effective, efficient and inexpensive tools to kill mold from surfaces and prevent its immediate recurrence. You can even keep a pre-mixed solution of bleach and water in a well-marked spray bottle on hand for managing recurrent mold problems which you can then wipe away with a towel soaked in hot water.

Mix 1 part household bleach to at least 3 parts hot water in a bucket or large bowl.

Pour the bleach solution on the moldy sealant or apply it with a rag soaked in the solution or a small brush. Allow the solution to set for approximately 5 minutes and wipe with a rag to see if any mold remains.

Scrub away persistent mold that may have formed in crevices in the sealant with a toothbrush dipped in the bleach and water solution. For very bad mold, lay a rag soaked in the hot water and bleach solution over the affected area and allow to sit for several hours.

Wet a clean rag in fresh hot water and rinse the affected sealant area well several times to remove any bleach residue or mold debris, rinsing out your rag in fresh water after each pass.

Things You Will Need

  • Household bleach Old toothbrush or narrow scrub brush Hot water Bucket or large bowl Clean rags Rubber gloves


  • Anytime you work with full strength bleach make sure you are in a well-ventilated area as fumes from the bleach can make you ill.