How to clean shower mold and keep it from coming back

Step by step: how to clean shower mold and keep it from coming back

Safety first. Never mix bleach with ammonia, vinegar or any other cleaner. Open a window, run the fan, and wear gloves, goggles and an N95 mask. People with asthma, allergies or a weak immune system should let someone else do the job.

1. 1

   Ventilate and gear up

   Open the window and the door, turn on the bath fan, and take out bottles, mats and the curtain. Put on gloves, goggles and an N95 mask before you disturb the mold. Scrubbing releases spores, and the cleaners give off fumes in a small room.

2. 2

   Check how big the problem is

   Look at the grout, the caulk, the ceiling over the shower and the wall outside it. Spots on surfaces are a DIY job. If the moldy area adds up to more than about 10 square feet, or the wall is soft or stained from behind, stop and call a professional.

3. 3

   Scrub with detergent and water

   Spray the moldy areas with dish soap in warm water or a tub and tile cleaner and scrub with a stiff nylon brush, using the grout brush along the joints. Rinse often. Most black spots on tile come off at this stage; stains left in grout need the next step.

4. 4

   Treat white grout with diluted bleach

   Mix about 1/3 cup of bleach into a gallon of cool water and apply it to the stained grout and glazed tile with a sponge or spray bottle. Keep it wet for 10 minutes, then rinse thoroughly. Do not use bleach on colored grout or natural stone.

5. 5

   Use hydrogen peroxide on colored grout

   For colored grout or where you do not want bleach, spray 3% hydrogen peroxide straight from the bottle, leave it for 10 minutes, scrub and rinse. Test a hidden joint first to make sure the color does not change.

6. 6

   Replace moldy caulk

   If black spots sit under the surface of the silicone, cleaning will not remove them. Cut the old caulk out with a utility knife or caulk tool, scrub the joint, wipe it with diluted bleach, and let it dry for 24 hours. Run a new bead of mold-resistant silicone and let it cure as the tube directs before showering.

7. 7

   Clean the ceiling and fixtures

   Wipe mold spots on a painted ceiling with a damp cloth and detergent rather than soaking it, and dry it. Check the shower curtain, the caddy and the bath mat, which grow mold too. Wash fabric items or replace them.

8. 8

   Dry everything completely

   Rinse, squeegee the walls, and towel-dry the grout lines and corners. Leave the fan on and the door open for at least an hour. Mold needs moisture, so a fully dry shower is the end of the cleaning job.

Can you clean shower mold yourself?

Yes, for mold on tile, grout and caulk. The EPA says that if the moldy area is less than about 10 square feet, in most cases you can handle the job yourself, scrubbing mold off hard surfaces with detergent and water and drying them completely.

The EPA also notes that absorbent materials such as ceiling tiles and carpet may need to be thrown away if they become moldy. In a bathroom, that includes moldy caulk, a bath mat, and drywall that is soft or stained. Call a professional if the mold covers a large area, keeps coming back from inside the wall, or followed a leak or flood.

How to use bleach on shower mold safely

Dilute it, ventilate, protect your skin, eyes and lungs, and never combine it with anything else.

• The CDC’s mold cleanup guidance says to use no more than 1 cup of bleach per gallon of water, never mix bleach with ammonia or any other cleanser, open windows and doors, and wear an N95 respirator, gloves and goggles.
• Clorox’s grout method uses a milder 1/3 cup per gallon, mixed fresh and left on for 10 minutes. That is plenty for most shower mold.
• Vinegar and bleach together release chlorine gas. If you cleaned with vinegar earlier, rinse the shower completely before using bleach.
• Bleach lightens colored grout and can damage natural stone; use hydrogen peroxide or a stone-safe cleaner there.

Black mold, pink slime and mildew: what is the difference?

Black or gray spots on grout and caulk are mold or mildew; the pink or orange film around drains and on the curtain is usually a bacterium, not mold. You clean both the same way.

Pink slime grows on soap residue in damp spots and returns quickly. Scrub it with detergent, rinse, and dry the area; wash the shower curtain liner too, as in our guide on how to clean a shower curtain. The color of a mold does not tell you how harmful it is, so treat any mold growth the same way: clean it up and fix the moisture. So if you are asking how to get rid of black mold in the shower, the steps above are the whole method: scrub it with detergent, use diluted bleach on white grout and glazed tile, and recaulk wherever the spots sit inside the silicone. For mold beyond the shower, see our guide on how to clean black mold.

How to stop mold coming back in the shower

Control moisture. The EPA’s guide to mold and moisture says the key to mold control is moisture control.

• Run the bath fan during every shower and for 20 to 30 minutes after; if you do not have one, open a window.
• Squeegee the walls and glass after the last shower of the day.
• Leave the shower door or curtain open so the stall dries.
• Wash bath mats and the curtain liner regularly, and keep the grout sealed.
• Fix dripping fixtures and failed caulk quickly, before water gets behind the tile.

Mistakes to avoid

• Mixing bleach with vinegar or an ammonia cleaner to make it work faster.
• Spraying bleach on moldy caulk and expecting the black spots under the surface to disappear.
• Using full-strength bleach, which is harsher on grout and lungs and works no better.
• Cleaning mold without gloves, eye protection or a mask in a closed bathroom.
• Painting or caulking over mold without removing it and drying the area first.
• Cleaning the visible spots but never fixing the fan or the moisture that caused them.