How to Remove Black Mold from Bathroom Silicone
Scrubbing will not shift mold in silicone caulk. Apply a gel mold remover and let time do the work.
What you need
Supplies
- Gel mold remover or chlorine bleach cleaner
Tools
- Paper towels
- Long rubber gloves
- Mask
- Toothbrush
- Dry towel
How to do it
- 01
Ventilate and dry the area
Open the bathroom door, turn on the exhaust fan and put on rubber gloves and a mask. Moisture dilutes the remover, so wipe the silicone dry first.
- 02
Apply the gel
Squeeze a thick line of gel mold remover along the moldy caulk. Gel does not run, so it stays put even on vertical seams.
- 03
Cover and wait
If you are using a spray, lay a thin twisted paper towel along the caulk and spray over it so it sticks. Leave it for the time on the label, usually 30 minutes to 2 hours.
- 04
Rinse thoroughly
Remove the paper towel and rinse well with the shower. Brush any remaining marks lightly with a toothbrush and rinse again.
- 05
Dry completely
Towel off the water and run the exhaust fan for at least an hour. The less time the silicone stays wet, the harder it is for mold to return.
Be careful
- Chlorine mold removers release toxic chlorine gas when mixed with acidic cleaners such as citric acid, vinegar or acidic toilet cleaners. Never use them on the same day.
- In a windowless bathroom, keep the door open and the fan running. If you feel dizzy or your throat stings, leave the room immediately.
- Splashes bleach colored bath mats, towels and clothes. Move them out first.
Malkkeum tips
- Squeegeeing the caulk line after showering and leaving the door open greatly reduces regrowth.
- Longer is not better. Follow the label time and repeat instead; it is gentler on the silicone.
- The day after cleaning, once the silicone is fully dry, an anti-mold bathroom coating helps the results last longer.
Why scrubbing does not work
Black mold on silicone is not only on the surface; it has rooted into the silicone itself. Brushing fades the top layer, but it turns black again soon after. A chlorine remover has to stay in contact for a while to soak in, break down the pigment and kill the mold.
If it will not go away
If black spots remain after two or three rounds, the mold has grown deep into the caulk. At that point the answer is recaulking, not cleaning. Cut away the old silicone, disinfect the joint with mold remover, let it dry completely and apply new anti-mold bathroom silicone. If you are not comfortable doing it yourself, hire a caulking professional.
FAQ
Can I use diluted bleach? Yes. Follow the mold-removal dilution on the label, mix it with cold water and soak paper towels to lay over the caulk. Liquid runs off vertical surfaces easily, though, which is why a gel is more convenient.
