How to Remove Mildew From Shower Tile Grout

Mildew thrives in warm, damp environments, so it's no wonder that the bathroom is one of its favorite locations. Mildew spores particularly like to grow on grout, that porous material in between shower tiles that just seems to attract stains. Not only does the gray or black discoloration look unsightly, but mildew can also trigger allergies in sensitive people. Cleaning grout can be tedious, but using a few inexpensive, natural products you likely have on hand can help make the process a little less painful.

hand with yellow rag cleaning the bathroom tiles
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Wiping your shower completely dry after each use helps prevent mildew growth.

Precleaning Grout and Tiles

Step 1

Dampen a clean sponge with warm water and wipe the area to be treated. If you don't get the obvious dirt, film and grime from the grout and tiles before treating the mildew, you'll just end up with a sticky mess.

Step 2

Loosen mildew spores growing on the grout with a stiff-bristled scrub brush or an old toothbrush. Scrub with a circular motion to get into all of the tiny crevices.

Step 3

Rinse the treated area clean with warm water. Pat the grout dry with a clean cloth.

Treating Light Mildew Stains

Step 4

Combine equal parts distilled white vinegar and warm water in a small spray bottle. Spritz the solution directly onto the stained grout.

Step 5

Allow the vinegar solution to sit for five to 10 minutes. This gives the mild acid in the vinegar time to penetrate and dissolve the mildew spores.

Step 6

Scrub the grout with a brush until the mildew stain disappears. Rinse the treated area thoroughly with warm water to remove all vinegar residue. Dry the treated area with a clean cloth.

Removing Moderate Mildew Stains

Step 7

Pour 3 cups baking soda into a medium-size container. Add about 1 cup of warm water, or just enough to create a thick paste. Stir until smooth.

Step 8

Slather the paste directly onto the mildewed grout. Use your scrub brush or an old toothbrush to work the paste into the cracks and crevices.

Step 9

Spray undiluted distilled white vinegar directly onto the paste. Wait until the mixture quits foaming and then scrub the area using a circular motion until no more mildew remains. .

Step 10

Wipe the paste from the grout using a damp, clean cloth. Rinse the area with clear water to remove any remaining residue. Dry the treated section with a clean towel.

Treating Stubborn Mildew Stains

Step 11

Combine equal amounts of chlorine bleach and warm water in a small spray bottle and give it a few good shakes. Liberally spray the solution directly onto the mildewed grout.

Step 12

Allow the bleach solution to stand for about 15 minutes so it can penetrate those stubborn stains. Scrub the treated area one grout line at a time with your brush, using a circular motion to get into all of the tiny crevices.

Step 13

Rinse the area thoroughly with warm water to remove all traces of mildew and bleach. Dry the tile and grout with a clean cloth. Repeat this process, if necessary.