How to Clean Shower Grout: Step-by-Step

Shower grout is porous and tends to trap soap scum, hard water minerals, and mildew, which can make it look dingy and even lead to mold growth. Regular cleaning keeps your shower looking fresh and helps maintain the integrity of the tile. Before you start, ensure the shower is dry and well-ventilated. If you have a grout sealer, check if it’s still effective—water should bead up on the surface. If it soaks in, you’ll need to reseal after cleaning.

What You’ll Need

Baking soda
Hydrogen peroxide (3% solution) or white vinegar
Small bowl or cup for mixing
Old toothbrush or stiff-bristled grout brush
Spray bottle (optional)
Clean water and a sponge or cloth
Rubber gloves and safety goggles (optional but recommended)
Old towel or rag

Step-by-Step

Prepare the area: Remove any items from the shower (shampoo bottles, soap dishes, etc.) and lay an old towel on the floor to catch drips. Open a window or turn on the exhaust fan to ensure good ventilation.
Make a cleaning paste: In a small bowl, mix baking soda and hydrogen peroxide (or vinegar) to form a thick paste. Start with about 1/2 cup of baking soda and add 2–3 tablespoons of liquid, stirring until it reaches a spreadable consistency. The paste should be thick enough to stick to vertical surfaces.
Apply the paste: Using your fingers (with gloves) or an old toothbrush, spread the paste generously over the grout lines. Focus on stained or discolored areas. Cover the entire grout surface if possible.
Let it sit: Allow the paste to sit for 10–15 minutes. This gives the baking soda time to break down grime and the peroxide to lift stains. For tough, set-in stains, you can leave it for up to 30 minutes, but don’t let it dry completely.
Scrub the grout: After the paste has sat, scrub the grout lines vigorously with your toothbrush or grout brush. Use small circular motions, working the paste into the pores. Pay extra attention to corners and edges where grime accumulates.
Rinse thoroughly: Once you’ve scrubbed all the grout, rinse the area with clean water. You can use a spray bottle filled with water or a wet sponge. Wipe away all the paste and loosened dirt. Repeat rinsing if necessary to ensure no residue remains.
Dry the shower: Use a clean, dry towel or rag to wipe down the tiles and grout. This prevents water spots and helps you see if any stains remain. If you notice any stubborn spots, repeat steps 2–6 on those areas.
Reseal (if needed): After the grout is completely dry (usually 24 hours), test if it needs sealing. Sprinkle a few drops of water on the grout. If the water beads up, the sealer is still intact. If it absorbs quickly, apply a grout sealer according to the manufacturer’s instructions to protect against future stains.

Common Mistakes

Using bleach on colored grout: Bleach can discolor or lighten tinted grout. Stick to gentler cleaners like baking soda and peroxide.
Scrubbing with metal brushes: Metal bristles can scratch tile surfaces and damage the grout. Always use a nylon or plastic brush.
Not rinsing thoroughly: Leaving cleaning residue can attract more dirt and cause a filmy buildup. Rinse well and dry.
Skipping the sealer: If you don’t reseal after deep cleaning, the grout will quickly become dirty again. Sealing is essential for long-term cleanliness.
Using too much water: Excess water can seep behind tiles if grout is cracked, leading to mold. Use a damp sponge rather than soaking the walls.

Tips

Clean grout regularly (every 2–4 weeks) to prevent heavy buildup. A quick wipe down after each shower helps.
For daily maintenance, use a squeegee on the walls and floor to remove excess water, reducing soap scum and mildew.
Use a fan or open a window during and after showers to reduce humidity, which discourages mold growth.
If you have very stubborn stains, make a paste with baking soda and water only, and let it sit overnight before scrubbing.
Always test any cleaning solution on a small, inconspicuous area first to ensure it doesn’t damage your tile or grout.

Troubleshooting

Stains remain after cleaning: For deep-set stains, apply a paste of baking soda and water, cover with plastic wrap, and leave for several hours or overnight. The moisture helps lift the stain. If that doesn’t work, you may need a commercial grout cleaner or a grout pen to recolor the lines.

Grout is crumbling or missing: If you notice cracks or missing chunks, you’ll need to repair the grout. Remove the damaged grout with a grout saw, clean the area, and apply new grout. This is a more involved project but prevents water damage.

Mold keeps coming back: Persistent mold indicates moisture problems. Ensure your shower is well-ventilated, fix any leaks, and consider using a mold-resistant grout sealer. If mold has penetrated deep, you may need to remove and replace the affected grout.

Cleaning solution is too harsh: If you experience eye or skin irritation, stop and rinse well. Dilute your cleaner or switch to a gentler solution like vinegar diluted with water (1:1).

Frequently Asked Questions

Can I use vinegar instead of hydrogen peroxide?

Yes, white vinegar works as a substitute for hydrogen peroxide. It’s effective against soap scum and mildew, but it has a strong odor. Mix it with baking soda to create a paste.

How often should I clean shower grout?

Ideally, clean grout every 2–4 weeks to prevent buildup. If you notice discoloration or mildew, clean it as soon as possible.

Will baking soda and vinegar damage my tile?

No, baking soda and vinegar are safe for most tile and grout. However, avoid using vinegar on natural stone tiles (like marble or travertine) as it can etch the surface.

Do I need to seal grout after cleaning?

Yes, sealing grout after deep cleaning helps protect it from stains and moisture. Check the sealer’s condition regularly and reapply as needed.

How can I prevent grout from getting dirty?

Use a squeegee after each shower, keep the bathroom ventilated, and clean regularly. Applying a good quality sealer also helps.

Can I use a steam cleaner on grout?

Yes, steam cleaners are effective at loosening dirt and killing mold without chemicals. Use the appropriate attachment and follow the manufacturer’s instructions.

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