How do you clean dirty tile grout?

How to clean tile grout step by step

To clean and restore tile grout, loosen the dirt with water and a suitable tile cleaner, scrub the joints with a stiff brush, then rinse and dry. Worn or cracked grout needs re-grouting instead, which the sections below cover.

1. Ventilate the room. Open the window and door, or turn on the exhaust fan, before you start.
2. Wet the grout. Wipe or sprinkle clean water along the joints so the cleaner spreads evenly.
3. Apply a tile cleaner. Use a suitable tile cleaner and leave it on for the time the label says.
4. Scrub along the lines. Work a stiff brush along each grout line in short strokes, one small section at a time.
5. Rinse and dry. Rinse with clean water, then wipe or squeegee the tiles dry.

HDB's home care guide on floor finishes says stained tiles or joints come from spills and dirt. For stubborn stains, the guide advises a suitable tile cleaning agent, used as the manufacturer's instructions say.

For routine grout cleaning, a mild product is usually enough. Test anything stronger on a hidden corner first.

Stains and mould on grout

Dark spots that keep coming back around the shower are often mould. Ordinary dirt stains usually lift with a second round of cleaner and scrubbing.

If you use a disinfectant on mouldy grout, the National Environment Agency (NEA) guidelines for cleaning and disinfecting residences say to keep rooms well ventilated during and after cleaning and disinfection, follow the product label and the manufacturer's recommended contact time, and spray the disinfectant onto a cloth rather than directly onto the surface. NEA notes that household bleach is a hypochlorite disinfectant. Never mix bleach with acid-based cleaners or ammonia.

Wipe the grout with the cloth, wait for the contact time on the label, then scrub, rinse and dry.

Do not combine products to make something stronger; see our guide on the dangers of mixing cleaning products. If mould has also spread to the ceiling, walls or silicone joints, see how to remove bathroom mould from the whole room.

If a grout line stays dark after two or three careful cleans, the stain may run deep, and re-grouting is the more reliable fix.

What damages grout

HDB's home care guide on floor finishes says loosened tile grout comes from excessive use of concentrated tile cleaner and from wear and tear. Its fix is to loosen the joint grout with a stiff brush and reinstate the joints with suitable tile grout.

In practice, use concentrated products only when a mild clean has not worked, rinse them off fully and use one at a time. Never mix bleach with acid-based cleaners or ammonia.

Tools matter too. Avoid wire brushes on glazed tile edges, where they can scratch the glaze. A stiff nylon brush is enough for most grout, while a knife or screwdriver can gouge the joints.

Some problems are not about the grout at all. If tiles sound hollow when you tap them, or start to lift or crack, cleaning will not help. See our guide to floor tiles popping before you spend more time scrubbing.

When to re-grout or call someone

Re-grout when the grout crumbles, cracks, has worn below the tile edges or stays black after a careful clean. A handyman or tiling contractor can refill the joints, or you can do small areas yourself.

Cracked tiles are a bigger job. HDB's home care guide on floor finishes says cracks come from impact or from the tile and the substrate under it expanding differently, and that cracked tiles should be removed and re-tiled if necessary.

HDB's renovation guidelines for building works say replacing floor finishes needs an HDB permit. In bathrooms and toilets, pre-packed waterproofing screed and a waterproofing membrane must be used before laying new floor finishes, with the membrane turned up at least 150mm against walls and kerbs. See also our guide to HDB floor tile rules.

The soft, flexible joint where tiles meet a bathtub, basin or shower tray is usually silicone sealant, not grout. For that, see our guide on replacing silicone sealant.

Keeping grout clean

Small habits keep grout cleaner for longer. Squeegee the shower walls and floor after each use so water does not sit in the joints. Keep the bathroom window open or the exhaust fan running until the walls are dry. Wipe kitchen spills as they happen, before they soak into the grout lines.

Once a week, give the grout a quick scrub with a stiff brush and warm water, paying attention to corners and the area around the floor trap. Rinse and dry as you go.

If the whole home needs more than a weekly scrub, for example before moving in, you can compare deep cleaning services. Ask the company whether grout scrubbing is included and how they handle mould. Price depends on the job.

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