How to Remove Mold from Shower Grout

Mold thrives in the porous environment of shower grout, feeding on soap scum and trapped moisture until those clean lines turn dark and fuzzy. It isn't just an eyesore; it is a breakdown of your bathroom's integrity that eventually leads to deeper sealant failure if left unaddressed. Getting rid of it requires more than a quick wipe. You need to break the bond between the biological growth and the porous cementitious grout. By using the right chemical agents to lift the spores rather than just bleaching them white, you ensure the mold stays gone and your bathroom stays hygienic for the long haul.

1. Dry the Grout First. Remove all bottles, loofahs, and racks from the shower. Use a dry microfiber cloth to wipe down the grout lines, ensuring they are completely dry before you apply any cleaning solution.
2. Mix Your Paste Now. Combine one part hydrogen peroxide with two parts baking soda in a small bowl until it forms a thick, spreadable paste. If you prefer a stronger approach, use a commercial-grade mildew remover gel.
3. Coat Every Moldy Line. Use an old toothbrush or a small grout brush to apply the paste directly into the grout lines. Ensure every spot of visible mold is completely covered with a thick layer of the mixture.
4. Let Chemistry Do Work. Leave the paste on the grout for at least 30 minutes. This dwell time allows the hydrogen peroxide or cleaning agents to penetrate the porous grout and neutralize the mold spores.
5. Scrub It Out Hard. Using a stiff-bristled nylon scrub brush, scrub the grout lines in a circular motion. Apply firm pressure to dislodge the loosened mold and grime from the porous surface.
6. Rinse Until Crystal Clear. Rinse the wall thoroughly with cool, clean water. Inspect the lines once dry; if any dark spots remain, repeat the process or use a specialty grout pen for permanent cosmetic touch-ups.