How to Whiten Grout in a NYC Apartment Bathroom
26.08.2026
To whiten grout, spread a thick paste of baking soda and water along the grout lines, let it sit about 10 minutes, then scrub with a stiff nylon brush and a little dish soap. Rinse, wipe dry, and repeat on stubborn spots. For a rental, finish with a clear grout sealer to keep the lines lighter longer.
What you'll need
- Baking soda
- A stiff nylon grout brush or an old toothbrush (not a wire brush)
- Liquid dish soap
- A spray bottle with warm water
- Microfiber cloths (reusable, easy to store in a small bathroom)
- Rubber gloves
- A clear water-based grout sealer, if you want the result to last
- An oxygen-based (oxygen bleach) powder for heavier staining, optional
Step by step
- Ventilate the room. If your bathroom has a non-opening window or no window at all, run the exhaust fan and leave the door open before you start.
- Rinse the tile with warm water so the grout is damp. Wet grout takes the paste better.
- Mix a paste: about three parts baking soda to one part water until it holds its shape like toothpaste.
- Spread the paste over the grout lines with the brush or a gloved finger. Focus on the lines, not the tile face.
- Let it sit for roughly 10 minutes so it can loosen buildup.
- Add a drop of dish soap to the brush and scrub each line firmly, working in short back-and-forth strokes along the grout.
- Spray with warm water and wipe with a damp microfiber cloth. Rinse the cloth often so you're not smearing gray residue around.
- For lines that are still dark, mix an oxygen-bleach powder with water per the label, apply, wait the label's time, then scrub and rinse again.
- Dry the whole area with a clean cloth. Grout that stays wet in a small NYC bathroom re-darkens fast.
- Once fully dry (give it a day), brush on a clear grout sealer following the product's directions. This is the step most renters skip, and it's the reason the white doesn't last.
What NOT to do
Don't reach for a wire brush or a scouring pad on glazed tile. Metal bristles scratch the glaze and gouge soft grout, which then traps more grime. Skip acidic cleaners like straight vinegar or lemon on natural stone or marble thresholds common in older buildings. Acid etches stone and eats away the grout itself. Don't mix bleach with any other cleaner, and never combine bleach and ammonia. In a tight bathroom with poor airflow, the fumes concentrate quickly. Finally, don't drench the wall behind the tile. Water seeping into old plaster or around a loose tile can cause bigger problems your landlord will notice.
When to call a pro
DIY handles surface staining on grout that's still intact. But if your grout is cracked, crumbling, missing chunks, or permanently discolored no matter how hard you scrub, that's a regrouting or deep-restoration job, not a cleaning one, and it may need your landlord's sign-off. Persistent dark spotting in the corners can also point to a moisture issue behind the tile that scrubbing won't fix. If you'd rather hand off a whole-bathroom refresh, including tile and grout, before a move-out inspection, book apartment cleaning with CleanWhale.
FAQ
Does baking soda actually whiten grout?
Baking soda is a mild abrasive, so it lifts surface staining and buildup when you scrub, which makes the lines look lighter. It won't restore grout that's been permanently discolored or dyed, and it isn't a disinfectant.
How often should I do this in a small apartment?
A quick baking-soda scrub every few weeks keeps grout from graying in the first place. Once you've sealed the lines, you can stretch that out, since sealed grout resists staining and wipes clean more easily.
Can I use bleach to whiten grout?
You can spot-treat white grout with a diluted bleach solution, but ventilate well, wear gloves, never mix it with other products, and keep it off colored grout and natural stone. In a windowless NYC bathroom, an oxygen-bleach powder is easier to work with and less harsh on the air.
Why does my grout turn dark again so quickly?
Usually because it was never sealed and stays damp. Steam radiators and long showers in a closed bathroom keep humidity high, so grout reabsorbs grime. Drying the tile after showers and applying a clear sealer are what actually make the whitening last.
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