Grout cleaning isn't the most glamorous job. But if you know how to clean grout properly, those grey, grimy lines can go bright again without spending a lot of money or an afternoon on your knees.
You don't need special products or any particular skill. Baking soda, white vinegar, an old toothbrush or scrubbing brush, and a bit of patience. That's the whole kit.
Here's the step-by-step.
What you'll need
- Baking soda (bicarb)
- White vinegar in a spray bottle
- Water
- An old toothbrush or a stiff grout brush
- A bucket and a cloth or sponge
- For stubborn cases: hydrogen peroxide (3% strength from the chemist) or a commercial grout cleaner
The toothbrush is the key tool. Nothing else reaches into grout lines as well, and an old one that's about to be binned works perfectly.
Step 1: Dry the tiles before you start
Wipe down the tiled surface and give it five to ten minutes to dry. Baking soda paste applied to wet tiles gets diluted and loses its grip. This job works better before a shower than after.
Step 2: Apply a baking soda paste to the grout
Mix baking soda with just enough water to form a thick paste, roughly the consistency of toothpaste. Press it directly into the grout lines using a spoon or your finger, working along each one.
Don't worry about being precise with the coverage. If some lands on the tile face, it'll wipe off later. Apply the paste generously and let it sit for five minutes before moving on.
Step 3: Spray with white vinegar and let it work
Fill a spray bottle with undiluted white vinegar and spray it over the paste. It'll fizz immediately. That reaction is the point: the acid in the vinegar breaks down soap scum, surface mould, and mineral deposits sitting in the grout.
Leave it for eight to ten minutes total. The longer the contact time, the better for particularly grimy lines.
Step 4: Scrub, rinse, and you're done
Take your toothbrush or grout brush and scrub along each grout line in short, firm back-and-forth strokes. The paste will have loosened most of the grime already, so you're shifting what's been broken down rather than fighting it.
Wipe off the residue with a damp cloth as you go. Rinse the whole area with clean water and dry it off. Satisfying, that.
How to clean grout that won't shift
Some grout, especially in older bathrooms or on shower floors, is stained deeper than the surface. A bathroom that hasn't had a proper clean in a while will likely fall into this category. The baking soda method will improve it, but might not fully restore the original colour.
A few options worth trying:
Hydrogen peroxide paste. Mix three parts baking soda with one part hydrogen peroxide (3% strength from the chemist is fine) to form a thick paste. Apply it the same way, leave it for 15 to 20 minutes, then scrub and rinse. It's stronger than the vinegar method and better suited to deep discolouration.
A commercial grout cleaner. If you have natural stone tiles (marble, travertine, limestone), skip any acidic options entirely. Vinegar and citrus-based cleaners can etch these surfaces. Use a pH-neutral cleaner designed for the tile type and check the label before applying anything.
A grout pen. If the grout is permanently stained but still structurally sound, a grout pen from the hardware store can refresh the colour on white or off-white lines. For grout that's cracked or crumbling, re-grouting is the only lasting fix.
What about mould in grout?
For black mould that keeps returning, the hydrogen peroxide paste above handles most surface cases. Persistent mould responds to a diluted bleach solution: one part bleach to four parts water, left on the affected lines for 15 minutes. Ventilate the room well and wear gloves. Don't mix bleach with vinegar or any other cleaner.
Keeping grout cleaner between jobs
Grout is porous, which means it picks up staining over time. The right habits won't keep it pristine forever, but they'll cut down on how often you need to do this job:
- Run the exhaust fan during and for a few minutes after every shower. Trapped moisture is the main driver of mould in bathroom grout.
- Wipe the shower walls down after each use with a squeegee or a dry cloth. Thirty seconds of effort saves a longer scrub down the track.
- Seal the grout once a year. Grout sealer fills the pores and makes surface staining easier to wipe off. Available from most hardware stores, and a low-effort job that pays off at every subsequent clean.
When it's a bigger job than a Saturday morning
The steps above handle most grout cleaning in a typical Perth home. But if the tile area is large, the bathroom or kitchen hasn't been thoroughly cleaned in a long time, or mould keeps returning faster than you can treat it, a professional house clean is a sensible way to reset things and start fresh.
Enhanced Cleaning works across Perth and Bunbury, handling deep cleaning for homes that need more than a maintenance tidy. The team is fully insured and police-checked, and every clean is backed by a satisfaction guarantee: if anything's missed, they come back and sort it.
Get a free quote and take one job off the weekend list.
