Removing mould from bathroom grout and preventing it

Short answer: first clean the joint with a suitable cleaner and a brush, rinse well and let the shower dry completely. If the black deposit is in the sealant itself or keeps returning, replacing the sealant is often the real solution. If the bathroom stays wet for a long time, mould will keep returning, however well you clean.

👷 Calling in a professional is never unnecessary. For large areas of mould, loose tiling, a leak behind the wall or health complaints, have a professional look first. Mould caused by a leak will not disappear with cleaning alone.

Grout or sealant: where is the problem?

In a cement joint you can often clean surface deposit. With Fila Brio universal cleaner or a Fila cleaner for floors and surfaces and a ABS sponge float you get a long way, for limescale a Fila descaling cleaner helps according to the directions. For cement haze on tiles, Fila Deterdek Pro cement haze remover is also used. If the sealant bead itself is black and soft, use Fila Zero Sil silicone remover and then apply new sanitary silicone sealant. Read in our blog on cleaning and renewing discoloured grout how cleaning and renewing grout fit together.

What do you need?

• A brush and a Raimondi floor sponge for scrubbing and rinsing.
• New grout where a joint is really missing: Kerakoll Fugabella Color grout for many tiling jobs or Kerakoll Fugalite Color grout where another grout type fits.
• Time to dry. Without drying time you judge too early whether cleaning was enough.

Step-by-step plan

1. Ventilate the bathroom and wear gloves before you start.
2. Clean a small area first and see whether the black colour comes out of the joint or only sits on it.
3. Scrub the joints along the joint and rinse the dirt away so it does not stand in the drain.
4. Let everything dry and check the sealant. Cut away and replace loose or black sealant.
5. Keep the shower drier: pull water off the tiles, ventilate after showering and leave the door or screen open. In our blog on cleaning while tiling you can read more about clean working with tiles.

Working safely

Wear work gloves with nitrile coating and safety goggles against splashes and a FFP2 dust mask when brushing dry deposit. Never mix cleaners, use one product at a time and rinse well in between. Ventilate during and after the work and keep children and pets out of the wet bathroom until everything is dry.

Does mould always come back?

If the joint is clean but the bathroom stays damp for a long time, the chance is high. Keeping it drier is therefore just as important as cleaning.

Can black sealant still be saved by cleaning?

Surface dirt can. If the colour is deep in the sealant or the sealant is loose, replacing it is neater and longer lasting.

Where can you find everything for this job?

At Saniso, the online store for DIYers and professionals, you will find tools, materials and personal protective equipment for your job.

• Browse our construction tools and our workwear and safety.
• Create a customer account and order easily.
• Working on a bigger project or want to hand over the job? Request a project quote.
• Book a showroom visit, at least 24 hours in advance.
• Not sure which material suits your job? Get in touch with us.

In doubt about the approach? Feel free to call in a professional.

Saniso – Build your home with Saniso.