Prep first
Before you start
- Stop the water source first, since mold needs moisture to grow.
- Gear up before you touch anything moldy.
- Brush loose mold off outdoors if you can, so spores don't scatter through the house.
Mold in a shower is a living fungus that spreads through tiny spores landing on wet surfaces, so it returns wherever moisture keeps collecting. On grout and other porous building materials it can fill the crevices and may be impossible to remove completely, which sometimes means replacing the piece. Fresh growth is far easier to clear than an old mark that has soaked into porous material.
Work the caulk line first, since it stays wet longest and is where black mold tends to dig in. A mold and mildew remover made for showers handles pink or black growth on grout better than a home mix. If the mold keeps coming back after two full rounds, that's your cue to call a pro.
Before you start
What showers & glass doors can take
Safe to use1
- Water
Use with care4
- Soaking
- Chlorine bleach
- Acids (vinegar, lemon)
- Scrubbing and abrasives
Avoid1
- Solvents (alcohol, spot removers)
6 items
What you'll need
Tap an item to get it on Amazon, or tick what you already have.
- GlovesKeeps spores off your skin. (opens Amazon)
- Goggles without ventsKeeps spores out of your eyes. (opens Amazon)
- N-95 respiratorStops you from breathing in spores while you scrub. (opens Amazon)
- Mild soap or detergentThe base cleaner for the scrub, mixed with warm water. (opens Amazon)
- Soft brush or spongeScrubs without abrasive pads, which can damage acrylic and cast iron. (opens Amazon)
- Clean clothDries the surface once it has been rinsed.
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6 steps
Step by step
Step 1 of 6
Ventilate and gear up
Open a window or run the bathroom fan before you start, so the air keeps moving. Put on gloves, goggles without vents and an N-95 respirator, and keep the spray and loose mold away from your face.
Step 2 of 6
Scrub the mold away
Work mild soap or detergent into warm water and scrub the moldy areas with a soft brush or sponge. Keep going until the dark spots lift off and the grout lines look clean.
Tip. Give extra time to the grout lines and corners, where water tends to sit.
Careful. No abrasive cleansers on acrylic, and no steel wool or abrasive pads on cast iron.
Step 3 of 6
Rinse everything right away
Rinse the whole area with clean water as soon as the scrub is done. Work so the dirty water runs down the drain rather than back over clean parts.
Careful. Cleaners must not soak on the surface, and overspray on nearby surfaces should be rinsed off.
Step 4 of 624 to 48 hours
Dry the surface completely
Wipe the walls, grout and caulk dry with a clean cloth, then leave the fan running or the window open until the area is fully dry. Wet areas that dry within 24 to 48 hours usually won't grow mold.
Step 5 of 6
Fix the water problem
Look for plumbing leaks, drips and any spot where water stays on the walls or the shower floor. Fix leaks as soon as you find them, and dry any items that got wet.
Step 6 of 6
Ventilate and clean more often
If mold comes back after everything has dried, run a fan or open a window during and after each shower. Then clean the surface more often, so new growth is caught before it spreads.
Tip. Keep a dry cloth by the shower to wipe down the walls after use.
If you'd rather buy than mix
Best products for mold on showers & glass doors
Check the label of any cleaner for your bath surface, and make sure it's safe for acrylic before you use it.
Amazon Basics Microfiber Cleaning Cloths
How we picked these: each product is made for this type of stain, its maker doesn't warn against using it on showers & glass doors, and its directions fit the steps above.
Finished the steps? How does it look?
Nice work. Let it dry completely and check it again in good light. Here is what done looks like:
How to tell it's really gone →A faint mark usually needs one more round, not a stronger product.
See what to do for what you're seeing →Heavy buildup usually takes more than one round.
Heavy or long-standing buildup →When to call a professional →How to tell it's working
The surface looks clean, and the grout lines have no dark specks left when you wipe them with a dry cloth. Everything feels dry to the touch, and the room has no damp smell when you come back to it.
What changes for yours
Adjust for your showers & glass doors
Caulk and caulking
Caulk is porous, so mold can settle into it and may be difficult or impossible to remove completely. Scrub it with the same soap and water, using a soft brush, and check it again once it's dry.
If the black stays in the joint after drying, the caulk may need replacing rather than more cleaning, because the mold is inside the material.
Mildew
Mildew on a shower is handled with the same steps as mold: scrub, rinse, dry and fix the water. The cleaning rules for your surface still apply, because the approach is the same.
If the stain is still there after a full scrub and drying, treat it as a set-in stain and read the set-in section before trying anything stronger.
Walls, grout, tile and shower head
Vinegar can damage cement grout, so skip it on the joints even though it's a common cleaner. Use the soft brush on tile and grout, and rinse thoroughly so no soap film holds moisture against the surface.
On painted walls, avoid hard scrubbing with baking soda. On the shower head or faucet, use only mild soap and warm water, because harsh cleaners can harm the PVD finish.
Pink, red or orange mold
The method is the same as for any mold on the same surface, so use the scrub, rinse and drying steps on pink, red or orange growth. Save anything stronger for last, since solvents are not safe on this surface.
If the color is still there after a full scrub and complete drying, it's a set-in stain, and the set-in section covers what's realistic.
Black mold
Black mold on a shower is handled with the same steps: gear up, scrub, rinse and dry. Dark growth in grout and caulk takes the most scrubbing, and porous material may not come fully clean.
If the dark stain doesn't lift after the scrub and full drying, it's set in, so the set-in section covers what to do next, including replacing porous material.
Musty smell
A musty smell means the room is still holding moisture, so the fix is drying and airflow rather than a stronger cleaner. Run the fan longer after showers and keep the window open until the walls are dry.
If the smell stays after the surface is clean and dry, look again for a leak or damp spot behind the tiles or in the shower base, and fix it before you clean again.
Heavy or long-standing buildup
Old mold has usually soaked into grout, caulk or porous material, so a surface scrub only reaches the top layer. Mold can fill small crevices and may be difficult or impossible to remove completely. No-scrub sprays can't reach into those crevices either, so there isn't a reliable way to skip the scrub.
Once everything is fully dry, check again, since what you see after drying is what's left. If it's still visible, the chlorine bleach option can be the last step, after everything is rinsed, in a ventilated room with the exhaust running outdoors.
For cast iron, a gentle abrasive used sparingly with water is the only harder option, and it has to be rinsed away right after. Keep abrasives off acrylic. If the mark stays after all of that, the material has likely been damaged, and replacing the caulk, grout or panel is the realistic fix.
Vinegar, baking soda, peroxide and more
Do home remedies work on mold on showers & glass doors?
Most home remedies were written for fabric or for hard surfaces with different needs, so only a few belong in a shower. Here is where each one lands.
Helps2Skip4Avoid1
Chemical safety
Never mix these
Some products in this guide react dangerously with each other. Use them one at a time and rinse with water in between.
Chlorine bleach + Hydrogen peroxide (3%)
Washington State's health department says bleach reacts with hydrogen peroxide, and Clorox says not to mix bleach with other household chemicals.
If they mix by accident: Don't use the mixture; ventilate the room and avoid breathing fumes or touching it; call Poison Control at 1-800-222-1222 for disposal advice or if anyone feels unwell.
What makes it worse
Mistakes to avoid
Don't mix bleach with ammonia or lemon juice
Mixing chlorine bleach with ammonia or any cleaner that contains it can produce toxic fumes. Don't combine it with lemon juice or vinegar either, and keep the room ventilated if you use bleach at all.
Don't paint or caulk over mold
Clean and dry the surface first, because paint over mold is likely to peel. Caulking over a moldy joint has the same problem, so clean the joint and let it dry before you seal it.
Don't tackle a large patch alone
Past about 10 square feet, or with mold from sewage or contaminated water, stop and follow professional remediation guidance. Hire an experienced professional when the job is that big.
Don't use full-strength bleach or ammonia in an airjet acrylic bath
Chemically active solutions can damage the surface of an airjet acrylic bath. Use only mild soap and warm water on it, and skip any aerosol cleaning products.
Troubleshooting
If the stain is still there
Pick what you're seeing:
Black spots remain in the caulk after scrubbing
Mold may have grown into the caulk itself, which can be impossible to clean completely. Clean and dry the joint fully before deciding whether to replace the caulk.
Mold is back within a week
Moisture is lingering too long. Add more ventilation, check again for leaks, and wipe the shower dry after each use.
The acrylic looks dull where you scrubbed
Stop using any abrasive on it. Dull or scratched acrylic needs repair through the manufacturer's customer service.
When to call a professional
Call a professional if the mold covers more than about 10 square feet, if it came from sewage or contaminated water, or if it keeps coming back after you've fixed the water. For dull or scratched acrylic, the manufacturer's customer service handles repairs.
Questions
Is shower mold dangerous to breathe?
Mold spores can be breathed in and can touch your skin, so cleaning calls for protection. Wear gloves, goggles without vents and an N-95 respirator, and open a window or run the fan.
Can I use bleach on shower mold?
Only as a last resort, because it isn't recommended as a routine practice. Use it after the surface is rinsed and the room is ventilated, with the exhaust running outdoors.
Does vinegar clean shower mold?
It can clean light mildew on hard surfaces, but it isn't a safe choice for cement grout or natural stone. For most showers, the mild soap and warm water scrub is the safer choice.
Can mold stains come out completely?
Sometimes. Mold can damage porous materials and may be difficult or impossible to remove completely, so a stain left after drying may be permanent.
Can old shower mold be removed without scrubbing?
Not reliably. Old growth sits in crevices that a spray can't reach, so the scrub is still needed, and the set-in section covers what to do next.
What mold cleaner should I buy for a shower?
Pick a mold and mildew product labeled for your bath surface, and check that it's safe for acrylic before buying. Use it as directed and rinse it off fully.
Why does mold keep coming back in my shower?
Mold needs moisture, so it returns when water keeps sitting on the surface. Fix leaks, run the fan or open a window, and clean more often.
Mold on other materials
Other stains on showers & glass doors
Start from the bigger picture
How we know this
Every method, amount and warning here comes from university extension services, industry bodies and product makers. We read them, check every step for unsafe combinations and changed amounts, and write it up so you can follow it.