The easiest way to clean grout is to make a paste of bicarbonate of soda and water, spread it along the grout lines, leave it for 10 minutes, then scrub with a stiff brush and rinse. For grout that has turned grey or black, an oxygen bleach solution or a steam cleaner will usually bring it back to its original colour.
Grout is porous, so it soaks up soap, grease and dirt far more than the tiles around it. That is why it ends up looking grubby even in a bathroom you clean every week. Our cleaners at ScrubbyDo deal with dirty grout on almost every deep clean and end of tenancy clean we do across Essex, so here are the methods we actually use, which one to choose, and how to keep grout looking new afterwards.
What you will need
You probably have most of this at home already:
- Bicarbonate of soda
- White vinegar (only for some grout, see below)
- Oxygen bleach powder, sold as an oxygen based stain remover
- Washing up liquid
- A stiff grout brush or an old toothbrush
- A spray bottle
- Microfibre cloths
- Rubber gloves
- A steam cleaner, if you have one
Before you start: check your grout and tiles
Not every grout cleaner is safe on every surface, so take a minute to check two things first.
Is your grout sealed? Drip a little water onto the grout. If it beads up, the grout is sealed. If it darkens and soaks in, it is unsealed and will need gentler treatment and a fresh coat of sealer once it is clean.
What are your tiles made of? Ceramic and porcelain tiles are tough. Natural stone such as marble, limestone and travertine is not. Acids like vinegar and lemon juice can etch and dull natural stone, so never use them on it.
Always test any method on a small hidden patch first.
How to clean grout: 6 methods that work
Start with the gentlest method and only move on if the grout still looks dirty.
1. Warm water and a stiff brush
For grout that just looks a little dull, this is often all you need. Spray the grout lines with warm water, scrub along each line with a stiff brush, then wipe dry with a microfibre cloth. Doing this once a week stops dirt building up in the first place.
2. Bicarbonate of soda paste (best for most homes)
This is our go to method for bathroom and kitchen grout.
- Mix 3 parts bicarbonate of soda with 1 part water to make a thick paste.
- Spread it along the grout lines with your finger or an old toothbrush.
- Leave it for 10 to 15 minutes.
- Scrub in small circles with a stiff brush.
- Rinse with clean water and dry with a microfibre cloth.
It is gentle, cheap and safe on almost every type of tile, including natural stone.
3. Bicarbonate of soda and white vinegar
For tougher dirt on ceramic or porcelain tiles, apply the bicarbonate paste as above, then spray it lightly with a mix of equal parts white vinegar and warm water. It will fizz. Once the fizzing stops, scrub the grout and rinse well.
Do not use vinegar on natural stone, and do not use it regularly on unsealed cement grout, because the acid can slowly wear it away.
4. Oxygen bleach (best for grey or stained grout)
Oxygen bleach is one of the most effective ways to brighten grout, and it is far gentler than chlorine bleach.
- Dissolve the powder in warm water following the instructions on the tub.
- Apply it to the grout with a brush or cloth.
- Leave it for 10 to 15 minutes so it can lift the stains.
- Scrub, then rinse thoroughly with clean water.
It works well on white grout that has gone grey and on floor grout that has picked up dirt from shoes.
5. Steam cleaning
A steam cleaner with a small nozzle or brush head is brilliant on floor grout and in showers. The heat loosens dirt and soap scum without any chemicals. Move slowly along each grout line, then wipe away the loosened dirt straight after. Avoid steaming unsealed natural stone, and check your tile manufacturer’s advice first.
6. A dedicated grout cleaner
If none of the above has worked, a shop bought grout cleaner made for your tile type is the next step. Follow the instructions carefully, ventilate the room, and rinse well afterwards.
How to clean black mould from shower grout
Black spots in shower grout are usually mould, and they need treating rather than just scrubbing.
- Open a window or turn on the extractor fan.
- Spray the area with a mould remover made for bathrooms, and leave it for the time stated on the label.
- Scrub with a grout brush and rinse well.
- Dry the area completely with a cloth.
If the mould has grown deep into the grout or keeps coming back within weeks, the grout may need raking out and replacing. Mould that returns quickly can also be a sign of a ventilation or damp problem.
Safety tip: never mix bleach with vinegar, ammonia or other cleaning products. The combination can release harmful fumes.
How to clean grout on a tiled floor
Floor grout gets dirtier than wall grout because it collects grit and spills. Sweep or vacuum first so you are not pushing grit into the lines. Then work in small sections of about one square metre:
- Apply bicarbonate paste or oxygen bleach to the grout lines.
- Leave it for 10 minutes.
- Scrub with a stiff brush or a grout brush on an extendable handle to save your knees.
- Mop with clean water, changing the water often.
- Dry the floor with a towel so dirty water does not settle back into the grout.
How to keep grout clean for longer
Once your grout looks good again, a few small habits will keep it that way:
- Seal it. Apply a grout sealer once the grout is completely clean and dry, and reapply every year or so in busy areas like showers.
- Squeegee the shower. Clearing water off the tiles after each shower stops soap scum and mould taking hold.
- Ventilate. Keep the extractor fan on during and after showers, or open a window.
- Wipe spills quickly. Coffee, wine and cooking oil stain kitchen grout fast.
- Give it a quick scrub weekly. Two minutes with a brush and warm water saves a big job later.
Common grout cleaning mistakes
- Using wire brushes or scouring pads, which scratch tiles and wear down grout
- Using vinegar or lemon on marble, limestone or travertine
- Leaving strong cleaners on for too long
- Not rinsing properly, which leaves a residue that attracts dirt
- Forgetting to reseal after a deep clean
When to call in a professional
If your grout is badly stained, covered in mould or you are moving out and want the bathroom and kitchen looking their best, a professional deep clean can save you hours. Our team cleans grout as part of every domestic deep clean and end of tenancy clean in Rayleigh, Southend, Basildon, Chelmsford and across Essex. Moving out soon? Our guide to end of tenancy cleaning prices shows what you should expect to pay in Essex.
Get a free quote, call us on 01268 261179, or send a photo of your tiles on WhatsApp.
Frequently asked questions
What is the best homemade grout cleaner?
A paste of 3 parts bicarbonate of soda to 1 part water is the best homemade grout cleaner for most homes. It is gentle enough for any tile and strong enough for everyday dirt.
Can I use bleach to clean grout?
You can use diluted chlorine bleach on white cement grout in a well ventilated room, but it can fade coloured grout and is harsh on your skin. Oxygen bleach is a gentler choice that works just as well on most stains.
How do you whiten grout that has gone yellow?
Apply oxygen bleach dissolved in warm water, leave it for 15 minutes, scrub and rinse. If the grout is still discoloured after a thorough clean, a grout pen or grout colourant can restore an even white finish.
How often should grout be cleaned?
A quick scrub once a week keeps grout looking good. Give it a deeper clean with bicarbonate of soda or oxygen bleach every month or two, and reseal it about once a year.
Does vinegar damage grout?
Used now and then on sealed grout between ceramic or porcelain tiles, diluted vinegar is fine. Used often, its acid can weaken cement grout over time, and it should never be used on natural stone.
