Clean and prevent mould in bathroom or kitchen grout using safe cleaning products and good ventilation.
MG-01Get set up and ventilate the roomOpen a window or turn on the extractor fan before you start. Mould cleaners give off strong fumes, so good airflow matters. Put on rubber gloves and, if you're using bleach, safety glasses too. Lay an old towel down to catch drips.
MG-02Test the cleaner on a small patch firstDab a little of your chosen mould remover onto a hidden bit of grout, like behind a shower curtain or under a sink. Leave it for a few minutes and check it hasn't discoloured the grout or damaged nearby sealant. Some coloured or old grout can bleach unevenly.
MG-03Apply the cleaner to the mouldy groutSpray the mould remover directly onto the affected grout lines, or make your own mix with one part bleach to four parts water in a spray bottle. Cover all the black or grey patches evenly. Avoid getting bleach on coloured grout or natural stone tiles, as it can bleach or etch them.
MG-04Leave the cleaner to workLeave the product on the grout for 10 to 15 minutes, or whatever time the bottle recommends. Don't let it dry out completely, as this makes it harder to scrub off. Keep the room ventilated while you wait.
MG-05Scrub the grout linesUse a small stiff-bristled grout brush or an old toothbrush to scrub along each grout line. Work in short strokes and go over any stubborn dark patches a second time. For tough mould, a paste of bicarbonate of soda and water left on for 10 minutes before scrubbing can help lift it.
MG-06Rinse and dry the areaWipe the grout down with a clean, damp cloth to remove all cleaner and loosened mould. Dry the area thoroughly with a separate dry cloth or towel, as damp grout attracts mould again quickly.
MG-07Treat any remaining stainingIf dark staining remains even after scrubbing, the mould may have gone into the grout itself. A grout whitening pen can cover light staining, but badly stained or crumbling grout should be raked out and reapplied instead. This is a separate, longer job if the grout has failed.
MG-08Reduce condensation to stop mould coming backMould in grout is almost always caused by trapped moisture. Run the extractor fan during and for 15 minutes after showers or baths, wipe down tiles after use, and leave the door or a window slightly open to let steam escape. This one habit does more than any cleaner to keep mould away long-term.
MG-09Clean up and store materials safelyRinse your brushes and cloths thoroughly under running water. Never mix leftover bleach solution with any other cleaning product, especially ones containing ammonia, as this creates dangerous fumes. Store bleach and mould remover out of reach of children, and wash your gloved hands before removing the gloves.
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