Look at the joint as well as the colour

Inspect with the shower dry. Is the bead firmly attached along both edges? Does it bridge an open gap, hide loose grout, or peel away where the tub moves? A discoloured but intact surface is different from a failed joint that admits water. Musty smells, soft adjacent finishes or dampness outside the shower point beyond routine cleaning.

Health Canada says mould returns unless its moisture source is resolved and recommends professional help when it recurs after cleaning. The guidance also identifies plumbing leaks, condensation and inadequate ventilation as possible moisture sources. Health Canada: Addressing moisture and mould indoors.

What does the joint tell you?

  • Intact surface with deposits

    Use compatible care and assess how the area dries.

  • Split or detached bead

    Correct the movement or adhesion problem before replacement.

  • Wet or damaged backing

    Investigate hidden moisture before resealing.

  • Growth returns after cleaning

    Arrange moisture and mould assessment.

Do not bury the old problem

A new layer over failing silicone cannot restore the bond underneath it. Where replacement is appropriate, remove the old material using methods that do not cut the waterproofing or scratch the fixture. If the joint is deeper or more complex than expected, stop and identify the assembly rather than digging toward the back of the wall.

The replacement sealant must be suitable for the materials and wet-area use. Follow its preparation, joint-shape and curing instructions. A surface that looks dry can still conceal wet backing. Do not rush the return to showering because the bead has formed a skin; use the product’s water-exposure time under the actual conditions.

Give the repaired joint a chance to dry

Remove standing water from ledges, keep bottles from trapping moisture against corners and run effective ventilation. Check that the fan actually exhausts and that the room has replacement air. These habits help with surface moisture but cannot repair a leak behind tile.

If a bathtub edge repeatedly pulls the bead apart, investigate tub movement. If the room remains wet long after showers, compare fan controls once the ventilation path itself has been checked. Sealant belongs at the end of a sound repair, not at the beginning of a guessing exercise.