How to Remove Mould From Your Shower Safely

Shower mould is one of the most common household problems in Australia. Warm water, soap residue, and poor ventilation create near-perfect conditions for mould spores to colonise grout, silicone, tiles, and fittings. Most shower mould you can clean yourself. Some of it you can't - and knowing the difference saves you time and protects your health.

Quick Summary

Before you start, assess the size of the mould-affected area. A patch smaller than one square metre on a hard surface - tiles, glass, silicone - is a DIY job. Larger than that, or mould that keeps returning after cleaning, calls for professional mould removal.

Check for signs of hidden moisture while you're at it. Grout that sounds hollow when tapped, tiles that shift underfoot, or a persistent musty smell after cleaning can all indicate water behind the wall. Surface cleaning won't fix a leak.

Safety and Prep Before Mould Removal

Put your PPE on before you disturb anything. Mould spores become airborne the moment you scrub or spray, and inhaling them causes respiratory problems, cold-like symptoms, and allergic reactions in sensitive people.

You need:

• Protective gloves (long rubber gloves for bleach-based treatments, nitrile for vinegar)
• Eye protection
• An N95 mask or half-face respirator rated P2 - standard dust masks don't filter spores

Open the bathroom window fully and run the exhaust fan before you begin. Keep both running throughout the job. Lay plastic sheeting on the shower floor to catch debris and contaminated rinse water, and keep it there until you're done.

Natural Mould Removal: Baking Soda and Vinegar

For families with children, pets, or anyone sensitive to chemical products, baking soda and white vinegar remove mould on shower tiles, grout, and glass without harsh fumes.

The combination works because vinegar is mildly acidic and kills around 80% of common mould species on contact. Baking soda is a mild abrasive that lifts residue and deodorises the surface at the same time.

Apply vinegar first. Spray it onto the mouldy area and leave it to soak for ten minutes. Then apply baking soda paste over the top. Scrub with a nylon brush, working the paste into grout lines and surface staining. Rinse with clean water and dry the area.

Make a Baking Soda Paste

Mix two parts baking soda to one part water to get a thick paste that stays on vertical surfaces without sliding. Apply it to the mouldy area with a cloth or spoon and press it into grout lines. Leave it for 15 minutes - contact time matters.

Scrub with an old toothbrush. The narrow head reaches into grout lines and around fitting edges that a larger brush misses. Rinse the area with clean water after scrubbing and check whether the staining has lifted. Repeat on stubborn spots before moving to stronger treatments.

How to Remove Mould From Shower Tiles and Glass

Spray your vinegar solution (undiluted white vinegar works, or nine parts vinegar to one part water for a milder mix) across tiles and glass surfaces. Leave it for ten minutes.

Wipe section by section with a microfibre cloth. Don't cover the whole shower at once - work in 30cm sections so the solution doesn't dry before you wipe it. For stubborn stains that the vinegar loosens but doesn't fully lift, apply baking soda paste directly to the spot, scrub with a toothbrush, and rinse.

Smooth surfaces like glass and glazed tiles clean up fastest. Textured tile surfaces and stone hold mould spores in their pores and need more contact time and elbow grease to get clean.

How to Remove Mould From Grout and When to Re-Grout

Grout is porous and absorbs moisture, which makes it one of the hardest surfaces to keep mould-free. Spray grout lines with undiluted white vinegar or a 3% hydrogen peroxide solution from a spray bottle. Leave for ten minutes, then scrub with a grout brush or toothbrush. Hydrogen peroxide penetrates slightly deeper than vinegar and bleaches mould staining at the same time.

After cleaning, inspect the grout. Grout that is crumbling, cracking, or deeply and persistently stained despite repeated cleaning needs replacing. Re-grouting cracked lines also prevents water from getting behind tiles and feeding hidden mould growth. Once new grout is fully cured (typically 72 hours), seal it with a grout sealer. Sealed grout is significantly harder to colonise.

Best Way to Remove Mould From Silicone Sealant

Silicone around the base of the shower, the screen frame, and the tap fittings is one of the first places mould establishes itself. It's flexible, sits in a constantly wet zone, and traps soap scum and dead skin cells - organic matter that mould feeds on.

Spray the silicone with a mould-specific bathroom cleaner or undiluted vinegar solution. Leave it for 20 minutes. Scrub with a soft brush - not steel wool or a stiff nylon brush, which damages the silicone surface and creates more gaps for mould to colonise. Rinse and check.

If mould keeps returning to the same silicone line within weeks of cleaning, replace it. Cut out the old silicone with a Stanley knife or silicone remover tool, clean the joint with methylated spirits, and apply fresh silicone. Mould that has penetrated the body of the silicone cannot be cleaned out.

How to Get Rid of Mould in Drains and Fittings

Remove the drain cover and inspect the drain mouth for built-up soap scum, hair, and organic matter. Mould grows on this build-up as much as on any other surface in the shower. Pour a cup of white vinegar or a diluted bleach solution down the drain, leave for ten minutes, then scrub the drain mouth and cover with a small brush.

Flush with hot water after scrubbing. Clean the drain cover separately in a bucket of warm soapy water, scrubbing both sides before replacing it.

For tap fittings and showerheads, soak a cloth in vinegar, wrap it around the fitting, and leave it for 20 minutes. Scrub visible mould with a small brush and rinse. Showerheads with mould inside the nozzle should be removed and soaked in a vinegar solution for an hour.

How to Clean Mould From Shower Curtains and Liners

Fabric shower curtains can go in the washing machine on a hot cycle with your normal detergent plus half a cup of white vinegar in the rinse cycle. Check the label first - most polyester and nylon curtains are machine-safe.

Plastic liners don't go in the machine. Lay the liner flat in a bathtub, fill with warm water, add a cup of baking soda and a cup of white vinegar, and leave it to soak for 30 minutes. Scrub mouldy spots with a cloth or soft brush, then rinse with clean water.

Dry curtains and liners fully before rehanging. Hanging a damp curtain is how the mould comes back within a week. If mould persists on the liner after two cleaning attempts, replace it - liners cost a few dollars and are not worth repeated treatment.

Why Black Mould Grows in Your Shower

Showers produce more moisture per square metre than almost any other room in the building. Steam rises and condenses on walls, ceilings, and glass. Poor airflow traps humidity above 70% relative humidity for hours after every use, which is the condition mould needs to colonise surfaces fast.

Soap build-up on tiles and grout provides organic matter that mould feeds on, accelerating growth on surfaces that would otherwise be too smooth to support it. Cracked or missing grout allows water to penetrate behind tiles where it sits against the substrate, feeding mould that never dries out between showers.

If black mould keeps returning in the same spot despite regular cleaning, look for a moisture source behind the surface rather than on it. Hollow-sounding tiles, soft grout, or a tile that moves when pressed all suggest water is tracking behind the wall, where fogging and remediation may need to be paired with physical removal.

How to Remove Stubborn Black Mould

For deeply stained black mould on grout and silicone that hasn't responded to vinegar or baking soda, use 3% hydrogen peroxide from a spray bottle. Spray, leave for ten minutes, scrub with a toothbrush, and rinse. Hydrogen peroxide bleaches staining as it kills the mould, so you'll see results on the surface even if repeat treatment is needed.

On persistent spots, apply the treatment twice in the same session with a full ten-minute soak each time. If the mould returns within two weeks of cleaning, the surface is retaining moisture that's feeding regrowth. At that point, the material needs replacing - not more cleaning.

Prevent Mould: Keep Your Shower Mould-Free

Run the exhaust fan during every shower and for 15 minutes after. If your exhaust fan vents into the roof cavity, it's adding moisture to the building rather than removing it - check where the duct exits.

Squeegee the walls and glass after each use. A 30-second squeegee removes most of the water film that would otherwise take hours to evaporate and sits available for mould spores to colonise. Store shampoo bottles and products on a draining shelf rather than directly on the shower floor - pooled water under bottles is a consistent mould hotspot.

Wash bath mats and towels weekly. Both stay damp after use and both sit in the wet area of the bathroom. A bath mat that never fully dries between uses feeds mould on the bathroom floor.

Fix dripping taps and showerheads the week you find them. A slow drip keeps the shower recess wet between uses and significantly increases mould growth rates on adjacent surfaces.

Long-Term Mould Removal and Maintenance

Clean the shower weekly rather than waiting for visible mould to appear. A five-minute spray-and-wipe removes the organic matter mould feeds on before colonies can establish. It takes far less time than removing entrenched mould from grout lines.

Reseal grout every two years and replace silicone every three to five years depending on condition. Both degrade with repeated wet-dry cycling and cleaning, and both become progressively harder to keep mould-free as they age.

In bathrooms without windows or with an undersized exhaust fan, run a small dehumidifier. Target 40–55% relative humidity. Above 60%, mould thrives. A dehumidifier in a poorly ventilated bathroom is the most reliable way to hold humidity in the safe range year-round.

When to Call Professional Mould Removal or Remediation

Call unmould if the affected area covers more than one square metre, if the mould is inside wall or floor cavities, or if it returns within two to three weeks of a thorough clean.

A professional inspection is also the right call if you suspect a hidden leak, if grout or tiles have moved or cracked in an area with no impact damage, or if the bathroom has a persistent musty smell you can't locate a source for. Hidden moisture behind shower walls causes structural damage and significant mould growth that surface cleaning doesn't reach, and in multi-unit or business settings often requires commercial mould remediation.

unmould covers Northern NSW with same-week bookings. The $385 call-out fee includes in-home attendance, humidity sensor readings throughout the property, visual inspection of all affected areas, a full written diagnosis report, and a recommended treatment plan. No obligation to proceed until you've seen the findings.

Call +61 419 964 797 or fill in the contact form.

Final Checklist Before Finishing

• All cleaned areas are dry to the touch and confirmed below 55% humidity
• Grout lines are intact and sealed
• Silicone has no black penetration remaining - replace any that does
• The exhaust fan is running and verified to vent outside
• A monitoring check is scheduled for one week after cleaning

If mould returns to the same spot within two weeks of a thorough clean, book a professional inspection. Returning mould means a moisture source that surface treatment alone won't fix.

Common Questions

How do I get rid of mould in my shower permanently? Fix the moisture source and keep bathroom humidity below 55%. Clean weekly to remove organic build-up before mould establishes, seal grout and replace silicone on a regular schedule, and run your exhaust fan for 15 minutes after every shower. Mould won't colonise a surface that stays dry.

How do I get rid of black mould in shower grout? Spray with undiluted white vinegar or 3% hydrogen peroxide, leave for ten minutes, and scrub with a grout brush or toothbrush. Repeat if staining persists. For grout that remains stained or crumbling after two treatments, re-grout the affected lines and seal the new grout once cured.

Is bleach or vinegar better to kill mould in the shower? For tiles and glass, bleach works faster and removes staining more thoroughly. For grout and silicone, vinegar or hydrogen peroxide penetrate better and are safer for household use with children and pets. Bleach kills surface mould but doesn't penetrate porous materials deeply. For regular maintenance cleaning, vinegar is the practical choice. For a one-off deep clean of badly stained tiles, diluted bleach gets results faster.

Will mould go away if it dries out? Mould spores go dormant when surfaces dry out but they don't die. The moment conditions return - humidity above 60%, available moisture, organic matter on the surface - they reactivate and the colony resumes growing. Drying alone is not a treatment. The mould needs to be physically removed and the moisture source addressed.