Why did my grout turn black after cleaning?

Author: Dan Langosh  |  Last update: Wednesday, June 25, 2025

The most benign may result from using too much soap and failing to wash it off properly. That leaves a film of dirt and soap, hence the discoloration. But it gets worse. Black grout can also be mold and mildew, which forms where there's moisture or high humidity.

Why is my grout still black after cleaning?

Grout will darken when it absorbs water. Even if the grout is sealed, a small bit of water may pool in some areas causing the grout in that area to appear darker on a regular basis. Squeegee the shower after using, otherwise you'll have to pull and replace tile to fix any low spots on the shower floor.

How do you get black stains out of grout?

To clean black grout, mix water and white vinegar. Then rub the solution on the grout using a toothbrush and let it sit for a few minutes before rinsing. You can also use a mixture of water, baking soda and dish detergent. But don't use bleach or hydrogen peroxide excessively as they cause discoloration.

How to get black off grout?

To clean black grout, mix water and white vinegar. Then rub the solution on the grout using a toothbrush and let it sit for a few minutes before rinsing. You can also use a mixture of water, baking soda and dish detergent. But don't use bleach or hydrogen peroxide excessively as they cause discoloration.

What does black grout mean?

Grout is porous and the black is mold growing in the grout, treat with a solution of bleach and water, when cleaned and dried seal with a grout sealer, they make products to Clean grout, 1.

Why is My Black Grout and Black Tile Hazing #tilegroutcleaning #efflorescence #hazing #blackgrout

How to fix black grout?

Mix equal parts white vinegar and warm water in a spray bottle. Saturate the grout completely with the vinegar solution, then let it sit for 5–10 minutes. Use a stiff brush (such as a nylon scrub brush) and a bit of elbow grease to start scrubbing the grout's surface.

What does black mold look like?

Black mold is a type of fungus that looks dark green or black. There are many kinds of black mold, but when most people refer to it, they're referring to Stachybotrys chartarum (S. chartarum). It grows and spreads on materials that contain a lot of cellulose, including paper products, wood products and drywall.

Does bleach ruin black grout?

Cleaners that contain bleach or ammonia can even fade the color of your grout, leaving you with an uneven appearance.

How do you remove black grout haze?

Homemade Grout Haze Remover

If you'd like to make your own grout haze remover and stay chemical-free, vinegar in conjunction with plain water can break up grout haze. Add three to four parts of distilled white vinegar to one part of cool water in a spray bottle. Mix but do not shake.

Does vinegar damage grout?

White vinegar is an acidic solution that can etch or corrode some tiles, particularly those made from natural stone or unglazed ceramic. The acid in white vinegar can also weaken and deteriorate certain grouts over time, particularly if the grout is already damaged or in poor condition.

Why does my grout turn black when wet?

Unsealed grout has tiny pores that absorb moisture, which can give unsealed grout lines a darker appearance. Once the moisture evaporates (assuming the moisture is not carrying dirt and contaminants), the grout lightens back up again. Most cement grout darken when wet.

How do professionals clean grout?

Steam cleaning is one of the most powerful ways to clean grout without the use of harsh chemicals. Professionals often use steam to loosen the dirt and other particles trapped in the grout without needing to scrub manually.

Can grout be stained black?

Grout Stain Color Options

Depending on where you purchase your grout stain, you can choose almost any color. Popular choices include white, gray, beige, ivory, taupe, and even black for a striking contrast.

How do you remove discoloration from grout?

To begin, combine 4 tablespoons of baking soda, white vinegar, and ammonia with 1 ½ quarts of warm water. Spray this solution onto the stained grout and allow to sit for about 15-20 minutes. Wipe clean and repeat as necessary. This solution can be used on both light and dark colored grouts.

Does grout haze remover work on mortar?

A pre-mixed, ready-to-use, mild acid solution. Removes dried Portland cement grout haze and mortar residue from tile, concrete and masonry.

Will a magic eraser remove grout haze?

Once you've activated the micro-scrubbers inside, your Magic Eraser is good to go. Start by swiping it firmly across the desired surface. In just a few swipes, you should start to see grout messes and buildup begin to disappear!

What happens if you wait too long to wipe grout?

As go-to grout and tile care specialists, The Grout Medic truly wants what is best for your tile. Waiting too long to wipe grout could result in unsightly grout haze. Don't wait too long to wipe off grout!

Will grout haze eventually go away?

Often, professional tile installers can avoid grout haze during the grout process. Will grout haze go away on its own? No, grout haze will not go away on its own and needs to be removed as soon as possible after installation to preserve the beauty of your new tiles.

Will hydrogen peroxide damage grout?

Yes, hydrogen peroxide is a natural neutral cleaner that is safe to use on grout. Hydrogen peroxide and baking soda produce oxygenated bleach, which is highly effective for cleaning grout.

Is OxiClean a good grout cleaner?

If you're trying to clean grimy grout between your bathroom shower or floor tiles, then OxiClean™ bathroom cleaners are here to help! They get rid of grout stains on vertical and floor tiles for a refreshed bathroom.

What is the problem with black grout?

Yes, unfortunately, black grout experiences fading over time. Grout is highly porous and will stain unless properly sealed. This is true of all grout colors (including lighter grout ). Even sealed grout, over time, won't prevent ugly stains from reappearing in areas where it is exposed to more water exposure.

What can be mistaken for black mold?

Aureobasidium

This yeast-type fungus can be mistaken for another more sinister and dangerous mold but is far less likely to make you sick. Aureobasidium can start as a slimy pink color, but it will turn brown or black and can look like black mold.

Is it safe to stay in a house with black mold?

Is it okay to be in house with black mold? Black mold can cause health problems. As such, it is not advisable to be in a house with black mold. If a person must stay in a house with black mold, they should try to seal off any areas where black mold is present to reduce contact with it.

How to tell the difference between mildew and black mold?

Mildew isn't as pungent in scent, and it looks more fluffy or powdery (but black mold, when cut off from its source of moisture, can take on a mildewy texture). House mildew is often also lighter in color, which is why you'll hear people talk about white mold vs. black mold in terms of good and bad.

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