Bathroom · DIY guide
How to remove mould from grout and silicone
Most bathroom mould is a ventilation problem wearing a cleaning-problem disguise. You can absolutely remove it yourself — but if it comes back within weeks, cleaning harder is not the answer.
Legal to DIY in Victoria
What you need
- Mould-specific cleaner, or white vinegar for light surface mould
- Stiff nylon brush (not wire — it scratches grout and tile)
- Gloves, eye protection, and open windows or the fan running
- Old towels to protect the floor
Step by step
Ventilate before you start
Open the window and run the exhaust fan. Mould cleaners and bleach in a small unventilated bathroom are genuinely unpleasant and, mixed with anything else, dangerous. Never combine bleach with vinegar or ammonia.
Treat the surface and wait
Spray the affected grout and silicone generously and leave it for the time on the label — usually 10–20 minutes. The waiting is what does the work. Scrubbing immediately just spreads spores around.
Scrub along the joint
Use the nylon brush along the length of the joint rather than across it. Rinse the brush often so you are not redistributing what you have just lifted.
Rinse thoroughly and dry
Rinse with clean water, then dry the whole area with a towel. Leaving cleaner residue in the joints attracts grime and can discolour grout over time.
Fix the cause, not just the symptom
Run the exhaust fan for 20 minutes after every shower — during is not enough, the moisture is still airborne. Squeegee the walls. Leave the door open. If your fan is not ducted outside, it is just moving damp air around the room and the mould will return regardless.
Common mistakes
- Mixing bleach with vinegar or other cleaners
- Scrubbing straight away instead of letting the product work
- Painting or siliconing over mould
- Assuming a noisy fan is a working fan — many are not ducted outside at all
When to stop and call someone
Black mould that returns within weeks, spreads onto painted plaster, or appears on the ceiling means moisture is getting somewhere it should not. That is either a ventilation failure or water tracking behind the tiles, and both need looking at properly.