How to Clean Grout Without Damaging It: A Singapore Home Guide
27 October 20266 min read
Quick answer: To clean grout safely, start with a pH-neutral cleaner or a baking soda paste and a stiff nylon brush, scrub along the lines, rinse with clean water and dry. For stains and mould, use oxygen bleach or 3% hydrogen peroxide, which are gentler on cement grout than chlorine bleach or acids. Avoid wire brushes and regular vinegar on cement grout, and seal it once it is clean and fully dry.
Grout is the most porous part of a tiled floor or wall. It soaks up oil, soap and water, and in Singapore's humidity it's often where mould shows up first. Scrub it too hard or with the wrong product, though, and you wear it away, which lets water get behind the tiles. This guide shows how to get it clean without causing damage.
What type of grout do you have?
Knowing your grout type tells you what it can handle.
| Grout type | How to recognise it | Can handle | Avoid |
|---|---|---|---|
| Cement grout, unsealed | Matte, slightly rough, darkens when wet | pH-neutral cleaner, baking soda, oxygen bleach, 3% hydrogen peroxide | Vinegar and acidic cleaners, wire brushes, frequent chlorine bleach |
| Cement grout, sealed | Water beads on the surface for a while | Same as above, gentler scrubbing | Harsh solvents that strip sealer |
| Epoxy grout | Slightly glossy, hard, doesn't darken when wet | Most household cleaners, including mild bleach solutions | Abrasive powders that dull the shine |
Most HDB flats, especially older ones, have cement grout. Many newer renovations use epoxy in kitchens and bathrooms because it resists stains better. If you're unsure, treat it as cement grout.
What you need
- A stiff nylon grout brush or an old toothbrush (never wire)
- Microfibre cloths and a bucket of clean water
- A pH-neutral floor or bathroom cleaner
- Baking soda
- Oxygen bleach powder (sodium percarbonate) or 3% hydrogen peroxide for stains and mould
- Gloves, and ventilation in bathrooms
- Grout sealer, if you plan to seal afterwards
Customers provide supplies for our cleaners too, so this list doubles as what to have ready if someone else is doing the job. Our list of cleaning supplies to prepare for a cleaner covers the rest of the home.
How to clean grout step by step
1. Clear and dry-clean the area
Sweep or vacuum floor tiles first so grit doesn't scratch the surface as you scrub. In bathrooms, rinse the walls with warm water to loosen soap.
2. Start with the gentlest cleaner
Apply a pH-neutral cleaner along the grout lines and leave it for a few minutes. Scrub with the nylon brush in short strokes along the line, not across it. Rinse and wipe. For everyday grime, this is often all you need.
3. Use baking soda paste for stubborn dirt
Mix baking soda with a little water into a thick paste. Spread it over the grout, leave it for 10 to 15 minutes, then scrub and rinse well. It's mildly abrasive but safe for cement grout.
4. Tackle stains and mould with oxygen bleach or hydrogen peroxide
- Oxygen bleach: dissolve in warm water following the label, apply to the grout, leave it to work for the time the label states, then scrub and rinse.
- 3% hydrogen peroxide: spray straight onto mouldy grout, leave for around 10 minutes, scrub and rinse.
Both lift dark staining and deal with surface mould without the strong fumes of chlorine bleach. Test first on a small patch if your grout is coloured, as both can lighten it slightly. For how these compare with bleach and vinegar, see bleach vs hydrogen peroxide vs vinegar for mould.
5. Rinse thoroughly
Cleaner left in grout attracts dirt and can affect sealer. Rinse with clean water twice and wipe up the excess.
6. Dry completely
Open windows and run the exhaust fan. In a humid Singapore bathroom, grout can stay damp for hours, so give it time before sealing.
Should you use bleach or vinegar on grout?
Chlorine bleach whitens grout fast, but used often it can weaken cement grout and fade coloured grout. It also mustn't come into contact with acidic toilet or limescale cleaners, since the mix releases chlorine gas. Use it occasionally on white grout if needed, with ventilation, and never alongside other products. Our guide to cleaning products you should never mix explains why.
Vinegar is an acid. Repeated use slowly dissolves the cement in grout, which leaves it rough and more porous. It's fine on epoxy grout and glass, but keep it off cement grout and natural stone.
Why grout mould keeps coming back
Mould on grout returns when the grout stays wet. In Singapore, that's most bathrooms. To slow it down:
- Squeegee shower walls and floor after use.
- Keep the exhaust fan clean and running after showers. A clogged fan barely moves air; see our guide on cleaning a bathroom exhaust fan safely.
- Fix leaking taps and blocked floor traps that leave puddles.
- Seal cement grout so water sits on top rather than soaking in.
If grout stays black after cleaning, the mould may be deep in the grout or the grout may be crumbling. Regrouting is then the real fix, which is a job for a tiler.
How to seal grout
- Make sure the grout is clean and fully dry, at least a day or as long as the sealer label says.
- Apply a penetrating grout sealer along the lines with the applicator or a small brush.
- Wipe any sealer off the tile surface before it dries.
- Leave it to cure for the time on the label before showering or mopping.
- Test once a year or so by dropping water on the grout. If it darkens quickly, it's time to reseal.
How often should you clean grout?
| Area | Light clean | Deep grout clean |
|---|---|---|
| Shower walls and floor | Every week as part of bathroom cleaning | Every few months, or when it darkens |
| Kitchen backsplash | Wipe after heavy cooking | Every few months |
| Living room and bedroom floors | With normal mopping | Once or twice a year |
The bathroom areas that get missed most often, including grout, are covered in our guide to toilet spots people always miss. For a broader reset, see our deep cleaning guide.
Frequently asked questions
What is the best homemade grout cleaner?
A paste of baking soda and water is the safest homemade option for cement grout. For stains or mould, use oxygen bleach or 3% hydrogen peroxide rather than vinegar, which can erode cement grout over time.
Can I use a steam cleaner on grout?
Steam can loosen grime in sealed or epoxy grout. On old, cracked or unsealed cement grout, it can push moisture in and loosen weak grout, so test a small area first.
How do I make grey grout white again?
Clean it with oxygen bleach and a stiff nylon brush, rinse and dry. If it stays grey, the colour may be permanent staining. A grout colourant pen or regrouting are the remaining options.
How long does grout sealer last?
It depends on the product and how much water the area gets. Showers wear sealer faster than living room floors. A simple water drop test tells you when to reseal.
Rather not spend your weekend on your knees scrubbing grout? A regular weekly or fortnightly clean at $23/hr keeps bathroom grout from building up, and you choose the products used. Book a cleaner or WhatsApp +65 8166 0891.