Safety First

Wear rubber gloves and open windows or turn on the exhaust fan when cleaning mould. Never mix bleach with vinegar or any other cleaner — the combination produces toxic chlorine gas.

Method 1: White Vinegar (Safe, Effective for Most Mould)

  1. 1

    Spray undiluted white vinegar directly on mould

    Pour white vinegar into a spray bottle. Spray generously — do not dilute it. Vinegar is effective against 82% of mould species and is safe on most tile and grout surfaces.

  2. 2

    Leave for 10–15 minutes

    Let the vinegar penetrate and kill the mould spores. Do not rinse off yet.

  3. 3

    Scrub with a stiff brush

    Use a stiff-bristled brush or old toothbrush for grout lines. Scrub vigorously. The mould should lift away. For textured tile surfaces, a scrubbing brush helps reach into the texture.

  4. 4

    Rinse thoroughly with warm water

    Rinse all surfaces completely. Dry with a cloth.

Method 2: Diluted Bleach (Heavy Mould or Black Mould)

  1. 5

    Mix 1 part bleach with 9 parts water

    Apply with a spray bottle or cloth. Leave for 10–15 minutes. Scrub and rinse very thoroughly. Bleach is more effective than vinegar for severe mould growth and kills a broader range of species.

Mould on Silicone Sealant

Mould grows deep into silicone sealant and is almost impossible to remove completely. Apply bleach solution and leave for several hours — this may clear surface mould but does not kill mould within the silicone. The only proper fix for heavily moulded silicone is to remove it entirely (cut out with a silicone removal tool or sharp knife) and replace with fresh silicone sealant.

Prevention is easier than cleaningRun the exhaust fan during every shower and for 15 minutes afterwards. Leave the shower door open after use. Squeegee walls after each shower — this removes 90% of the moisture that mould needs. Spray with diluted vinegar weekly as a preventive measure. Mould needs moisture, warmth and organic material (soap scum) — remove moisture and you remove the mould.

Frequently Asked Questions

Common household shower mould (typically Cladosporium or Aspergillus) causes issues primarily for people with mould allergies or asthma. Black mould specifically (Stachybotrys chartarum) can cause more serious respiratory issues but requires consistently wet conditions to grow and is less common in showers. If you have extensive black mould growth, especially on walls beyond the shower, consult a professional.
Insufficient ventilation is the most common cause. The bathroom exhaust fan may be too small for the space, not working properly, or not being run long enough. Check that your fan actually vents to outside (not into the roof cavity). Upgrade to a larger fan if needed — proper ventilation is far more effective than any cleaning product at preventing shower mould.