Grout is porous, so it absorbs dirt, soap scum and stains that tile shrugs off. Cleaning it takes a little elbow grease, and sealing it afterwards keeps it clean much longer.
Key Takeaways
- Start mild: warm water and a stiff brush, then a pH-neutral tile cleaner.
- A paste of oxygen bleach powder and water works on many stains.
- Never mix bleach with ammonia or acids; the fumes are dangerous.
- Seal cement-based grout after cleaning to resist stains.
Check your grout and tile
Most grout is cement-based. Epoxy grout is more stain-resistant. Natural stone tiles such as marble can be etched by acidic cleaners, so check before using vinegar or acidic products.
Step 1: Warm water and a brush
Spray warm water on the grout and scrub with a stiff nylon grout brush. Wipe up the dirty water with a cloth or sponge. Sometimes this is enough.
Step 2: A pH-neutral cleaner
Use a commercial tile and grout cleaner labelled safe for your surfaces. Follow the label and scrub.
Step 3: Oxygen bleach paste
For stubborn stains, mix oxygen bleach powder (sodium percarbonate) with water into a paste, apply it to grout lines, let it sit as directed and scrub. Rinse well. Oxygen bleach is generally gentler on coloured grout than chlorine bleach, but test a small area first.
Mould and mildew
For mould in showers, use a product designed to remove mould and mildew and follow the label carefully. Ventilate the room. Never mix chlorine bleach with ammonia, vinegar or other acids.
Steam cleaners
Steam cleaners can loosen grime from grout, but check that they are suitable for your tile and grout.
Seal the grout
After cleaning and letting the grout dry completely, apply a penetrating grout sealer according to the instructions. Sealers make grout more resistant to stains and moisture. Reapply according to the product’s guidance.
When to regrout
If grout is crumbling, cracked or missing, cleaning will not fix it. Small sections can be removed with a grout saw and replaced. Large jobs may need a professional.
Keep it clean
- Squeegee shower walls after use.
- Run the exhaust fan during and after showers.
- Wipe spills on floor grout quickly.
- Clean regularly with a mild cleaner.
Frequently Asked Questions
Can I use vinegar on grout? Vinegar is acidic and can damage unsealed cement grout and natural stone over time. Use cautiously, if at all.
What about baking soda? Baking soda paste can help as a mild abrasive.
How long does sealer last? It varies by product and use; check the label.
The bottom line
Start mild, use oxygen bleach for stains, never mix cleaners, and seal grout once it is clean.
