Light cleaning happens whenever you mop, but grout lines benefit from a focused scrub every 3–6 months, depending on how quickly they darken. In bathrooms and kitchen floors, where moisture and spills are common, you might need to tackle them more often.
When grout starts turning grey or brown, it’s usually dirt, soap scum or mild mould taking hold. A small brush (old toothbrush works) and a suitable cleaner can lift a lot of it in a short session. Doing this regularly is much easier than waiting years until it becomes almost black and stubborn.
Sealed grout stays cleaner longer, so if you’ve just installed new tiles or done a big deep clean, applying a grout sealer can buy you time. Even then, ignoring it forever isn’t an option.
Treat grout cleaning like a periodic chore – not daily, not yearly, but something you revisit a few times a year for the most used areas. Your tiles will look fresher and the whole room feels cleaner.