Do you usually neglect grout while tidying up your home? Your priority is the greasy countertops and messy fridge, right? And then after some time, you suddenly notice your grout has lost its initial color and shine. This can ruin the look of your bathroom and kitchen, and it’s also a potential health threat since bacteria can get trapped in these crevices.
The good news is that most discolored grout is dirt, not damage, and it comes out with a paste you can mix in a cereal bowl. Below: what to use, what to avoid (two of the internet’s favorite grout cleaners quietly dissolve it), how to handle shower grout, and how to keep it clean once you’ve done the work.
What is the best thing to use for cleaning grout?
If you’re looking for the best solution for your grimy and unattractive grout, you don’t need to rush to the store and waste money on commercial products that can potentially endanger your health.
The most efficient cleaning agents are probably already in your house. They’re baking soda, white vinegar, and lemons. Here’s why:
Baking soda and hydrogen peroxide
The best all-round option. Baking soda scrubs without scratching tile, and 3% hydrogen peroxide (the brown one from the pharmacy) lifts stains and kills the mildew that lives in grout pores. Mixed into a paste, they whiten grout that has been gray for years. It’s the same paste that works on sinks. Safe on ceramic, porcelain, and natural stone.
Oxygen bleach
Sodium percarbonate, sold as OxiClean and similar powders. Dissolve it in warm water, pour it over floor grout, wait an hour, scrub. It’s the heavy-duty option for a whole floor and it won’t discolor colored grout the way chlorine bleach does.
White vinegar (with a caveat)
Vinegar handles mildew and soap buildup on ceramic or porcelain tile, and it dissolves limescale around shower fixtures. It’s also an acid, and acids eat cement-based grout. Dilute it 1:1 with water, use it only on sealed grout, rinse well, and never use it on marble, travertine, or any natural stone. If you’re not sure your grout is sealed, use peroxide instead.
What about lemon juice?
Same problem as vinegar, weaker cleaning power, and it leaves sugar behind for the mildew to eat. Save the lemons.
What you need
A toothbrush works for one tile. For a floor, you’ll hate yourself by row three. Get:
- A stiff nylon grout brush (the narrow V-shaped kind fits the line)
- A spray bottle for peroxide or diluted vinegar
- A bucket of clean rinse water and old towels
- Rubber gloves, especially with oxygen bleach
- A drill brush attachment if the floor is large. Ten dollars, saves an hour.
How do I clean my grout at home?
Vacuum or sweep first so you’re not pushing grit into the lines. Then pick the method that matches the mess:
Method 1: Baking soda and peroxide paste (most stains)
Mix three parts baking soda with one part hydrogen peroxide and a squirt of dish soap. Spread it along the grout lines with a finger or a spoon, wait 15 minutes, scrub with the grout brush, rinse with clean water, and dry with a towel. Repeat on tough spots. Work in small areas so the paste doesn’t dry out.
Method 2: Oxygen bleach soak (whole floors)
Dissolve the powder in warm water at the ratio on the tub. Pour it over the floor so the grout lines stay wet, wait 30 to 60 minutes, scrub, then mop with clean water twice. Keep pets out of the room until it’s dry.
Method 3: Diluted vinegar (mildew on sealed ceramic or porcelain)
Mix equal parts white vinegar and water in a spray bottle. Spray the grout, wait ten minutes, scrub, rinse thoroughly. Skip this on natural stone and on grout you know is unsealed.
Method 4: Steam (no chemicals at all)
A handheld steam cleaner with a grout nozzle blasts dirt and mildew out with heat alone. Slow, but effective, and the only option that gets into the pores without scrubbing. Rinse and dry afterward.
How to clean grout in the shower
Shower grout has a different problem: it’s wet 20 minutes a day and never fully dries, so the gray is usually mildew, not dirt. Scrubbing helps for a week. Killing the mildew helps for months.
Spray undiluted 3% hydrogen peroxide on the grout, leave it for 30 minutes, scrub with the grout brush, rinse. For black spots that won’t budge, apply the baking soda and peroxide paste and let it sit for an hour. Then run the exhaust fan 20 minutes after every shower and squeegee the walls. The squeegee takes 30 seconds and does more than any cleaner.
How to keep grout clean
Cleaning grout is a project. Keeping it clean is a habit.
- Seal it. Drip water on a grout line. If it soaks in and darkens, the grout is unsealed. Apply a penetrating grout sealer after a deep clean and again every year or two. Sealed grout wipes clean instead of absorbing whatever lands on it.
- Rinse after mopping. Dirty mop water settles in the lines. Mop with a clean bucket, or go over floors once with plain water.
- Squeegee the shower. Thirty seconds a day beats an hour a month.
- Ventilate. Mildew needs moisture. Fans, open windows, and a bath mat that dries fully.
- Wipe spills fast. Coffee, wine, and pet accidents stain grout within hours.
When cleaning won’t fix it
Some grout is past saving. If it crumbles under the brush, has cracks you can fit a fingernail into, or stays black after peroxide and steam, the mold is below the surface and the grout needs replacing. Regrouting a shower is a weekend job with a grout saw and a float, or a few hundred dollars for a tile pro. A grout pen is a cosmetic fix that paints over the color, and it works for a year or so on floors nobody inspects closely.
Rather hand the brush to someone else?
Grout is the kind of job that takes an hour to plan and four hours to do. If you’d rather skip it entirely, MaidThis connects you with screened, vetted cleaners in more than 40 US cities, from Los Angeles to Philadelphia to Tampa. Book a one-time deep clean or a recurring schedule, flag the grout as a special request, and let a pro take the knee pads.
