How to clean shower mold and keep it from coming back

The short answer: to clean shower mold, ventilate, put on gloves and scrub the tile, grout and caulk with detergent and warm water, then treat leftover stains.

• Stains: undiluted white vinegar or 3% hydrogen peroxide
• Never combine cleaners, one spray bottle each
• Black inside caulk after treatment means the caulk needs replacing
• Rinse well and dry the shower completely
• Next step: Plan it with the Cleaning Schedule ($4.49).

To clean shower mold, open a window or run the fan, put on gloves, scrub the moldy tile, grout and caulk with detergent and warm water, then spray any stains left behind with undiluted white vinegar, 3% hydrogen peroxide or a bleach cleaner diluted as its label directs. Let it sit, scrub with a stiff brush, rinse well and dry the shower completely. Mold that stays black inside caulk after treatment has grown underneath it, and the caulk needs replacing. Below are the supplies, step-by-step methods for each surface, the safety rules and a simple routine that keeps mold from coming back.

Shower mold or mildew?

Mildew is a surface mold that looks gray, white or pinkish and wipes away fairly easily. Darker black or green spots that stain grout and caulk have often grown deeper. You clean both the same way; the difference is how much scrubbing they need and whether the caulk has to go.

What you need

Safety first

The EPA's mold cleanup guide says to scrub mold off hard surfaces with detergent and water and dry them completely. EPA's brief guide to mold and moisture warns never to mix chlorine bleach with cleaners that contain ammonia, because the fumes can be toxic. It also says to avoid breathing in mold and to wear gloves and goggles while you work. The CDC's home cleaning guidance adds to follow the product label and keep the room ventilated.

• Run the exhaust fan or open a window the whole time.
• Use one cleaner at a time and rinse well before switching.
• Never mix bleach with vinegar, ammonia or other cleaners, and never put vinegar and peroxide in the same bottle.
• If you have asthma, allergies or other health concerns, ask a doctor before tackling mold yourself.

How to clean shower mold, step by step

1. Ventilate and gear up. Turn on the fan, open a window and put on gloves and goggles.
2. Clear the shower. Remove bottles, razors and the curtain or bath mat.
3. Scrub with detergent. Wet the walls, then scrub tile, grout and caulk with warm water and dish soap. This alone lifts light mildew.
4. Treat the stains. Spray leftover spots with vinegar or hydrogen peroxide and wait about an hour. For stubborn stains on tile and grout, use a bleach cleaner exactly as the label directs instead.
5. Scrub again. Work grout lines with a stiff brush and caulk with an old toothbrush. A baking soda paste adds gentle grit.
6. Rinse. Rinse everything with clean water, top to bottom.
7. Dry. Squeegee the walls, wipe the caulk and leave the fan running until the shower is fully dry.

How to clean mold by surface

When the caulk has to go

Caulk is soft and slightly porous, so mold can grow underneath where no cleaner reaches. The EPA notes that absorbent materials that become moldy may need to be removed rather than cleaned. If black spots stay after a peroxide treatment, cut out the old caulk with a utility knife or caulk remover. Clean and dry the joint, then apply a mildew-resistant silicone caulk and let it cure for the time on the tube before showering.

How to keep mold from coming back

Mold needs moisture. The EPA's guide to mold and moisture recommends venting bathrooms, fixing leaks and keeping indoor humidity below 60%, ideally between 30% and 50%.

• After every shower: squeegee the walls and door and leave the fan running.
• Weekly: spray and scrub the tile, grout and floor, then rinse and dry.
• Monthly: check the caulk, wash the curtain and liner and wipe the ceiling.
• Every season: look for loose tiles, cracked grout or a slow drip and fix them early.

If your shower tile still looks dull after the mold is gone, a full bathroom cleaning checklist covers the rest of the room, and our deep cleaning checklist works through the whole house.

When to call a professional

Call in help if the moldy area is larger than about 10 square feet, if you smell mustiness behind the wall, if tiles are loose or soft or if mold returns within days of cleaning. Those signs point to a hidden leak or trapped moisture that cleaning can't fix.

Put it on your cleaning schedule

Shower mold comes back when the weekly scrub slips. A written routine keeps it small enough that a spray and a brush always do the job.

Our Cleaning Schedule ($4.49) is a 9-page printable with daily, weekly and monthly checklists, a seasonal deep clean list, room-by-room checklists, a family chore chart and a cleaning supplies list. Put "squeegee the shower" on the daily page, "scrub tile and grout" on the weekly page and "check caulk and wash the curtain" on the monthly page.

If you want to organize the whole house at once, the Home Management Bundle ($16.99) includes the Cleaning Schedule along with the Household Binder, Home Maintenance Log, Home Inventory, Moving Planner and Password & Accounts Log. Bought separately, those six come to $32.94. The maintenance log is a handy place to record when the caulk was replaced.

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Mold and soap scum often start at the drain, so finish the job with our guide on how to clean a shower drain, including a routine to keep it fresh between deep cleans.