How to Get Rid of Shower Mould and Keep It Away

Mould in a shower is common and usually cosmetic. It is also the thing most people attack with the strongest product available, which is rarely the right approach.

Why it grows

Mould needs moisture, warmth and something to feed on. A bathroom supplies all three. Soap residue and body oils on grout and silicone are food, the room is warm, and after a shower it stays damp.

It concentrates on silicone and unsealed or worn grout because those are porous or slightly textured, so they hold moisture and residue while the glazed tile face does not.

That is the key insight: mould is a moisture management problem showing up on the most absorbent surfaces. Cleaning treats the symptom.

Removing it from grout

For surface mould on sound grout:

1. Ventilate the room before you start, especially if using anything strong.
2. Apply a mould-specific bathroom cleaner to the affected lines and let it dwell for the time on the label.
3. Agitate with a stiff nylon brush.
4. Rinse thoroughly and dry.

If mould keeps returning to clean grout, the grout has likely lost its sealer and is absorbing moisture. Once it is clean and fully dry, reseal it.

Avoid making bleach the routine. It lightens the stain rather than removing the growth, and it degrades many grout sealers, leaving the grout more absorbent than before, which makes the next occurrence faster.

Removing it from silicone

Silicone is the harder one, and the honest answer is often that you cannot.

Mould gets into silicone rather than sitting on it. Once it has, surface cleaning removes the top layer and the growth underneath keeps going. Cleaner after cleaner will look like it worked and then the black comes back within a fortnight.

At that point, replace the silicone. Cut out the old bead completely, clean the joint back to bare tile, let it dry properly, and apply new. Mould-resistant sanitary silicone is worth using.

Silicone is a consumable. It has a finite life in a wet area and replacing it every few years is normal maintenance, not a defect. A shower with fresh silicone and clean grout looks dramatically better for very little money.

Keeping it away

This is the part that actually works.

Ventilation. Run the exhaust fan during the shower and for 20 minutes afterwards. Most bathroom fans are undersized or vent into a roof space rather than outside, both of which limit how much they help. If your fan is not clearing the mirror reasonably quickly, it is not doing enough.

Squeegee. Thirty seconds on the walls and screen after each shower removes most of the water that would otherwise sit there for hours.

Leave the door open after showering so the room dries faster.

Keep grout sealed, so it absorbs less.

Deal with soap residue. Regular cleaning of tiles and grout removes the food source.

Do these and mould becomes an occasional nuisance rather than a monthly battle.

When it means something else

Mould that returns within days, in the same specific spot, despite decent ventilation, is worth a closer look. Especially:

• Along the wall to floor junction
• In one corner only, while the rest of the shower stays clean
• Accompanied by drummy tiles, efflorescence, or staining on the ceiling below

Persistent localised mould can mean moisture is arriving from behind rather than from the shower. In that situation, no amount of cleaning will resolve it, because the surface is being wet from the other side.

The summary

Clean the grout and reseal it. Replace the silicone rather than cleaning it repeatedly. Then fix the drying, because that is what determines whether it comes back.

The full maintenance guide is here, and our tiling services cover regrouting and resealing if the shower has gone past what cleaning will fix.