Color: As the name suggests, black mold appears black or dark greenish-black. However, it can also have a greenish or grayish tinge. Texture: Black mold on grout often has a slimy or fuzzy texture.
Visual Signs
Look for physical growth in the above areas. If you notice black, blue, green, or pink growth appearing in water-prone areas (most commonly your grout), it's a sure sign you have mold issues. Mold will also grow under tiles, weakening their hold and lifting them.
The presence of small, hard lumps or clumping means the grout may have started to mix with water vapor. Clumps or lumps mean the grout is bad or is going bad. But if the grout is powdery, like a bag of fresh flour, it is probably perfectly fine.
Oxygen Bleach, Chlorine Bleach, or Hydrogen Peroxide: Stubborn mildew stains call for more potent solutions. Spray the affected grout with oxygen bleach, chlorine bleach, or hydrogen peroxide, ensuring the solution saturates the stains. Let it dwell for several minutes, then scrub the area.
Stain Removal: The Magic Eraser can help remove stains from grout, especially those caused by dirt, mold, or mildew. The abrasive texture can scrub away grime effectively.
Use the stain-fighting power of OxiClean™ Foam-Tastic™ to remove crusty stains from hard water, lime and calcium—in addition to grease and dirt. Plus, Foam-Tastic™ works on more than vertical tile surfaces and grout!
LTP Grout Stain Remover is a powerful solution for tackling stubborn stains and mould on grout. It's particularly effective on cement-based grouts, which are commonly found in homes and more domestic settings.
Vinegar is better at killing mold because it can work on both porous and nonporous surfaces. It also terminates molds at their roots so the mold won't return and is also safer than bleach. You can even combine it with baking soda to make it more effective.
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.
Cracks, staining, and black mold are some of the signs that your old grout may need to be replaced, but with skilled professionals it can often be renewed.
The best answer, in a word, is money. It costs more time and material to seal grout and there is little or no perceived benefit (until, of course, the grout gets stained or starts to crack). A superior product would cost more to purchase and install, again for no perceived benefit over the less costly unsealed grout.
Grout and tiling can create perfect little environments, or breeding grounds, for mold. As harmless as it may seem, ignoring the mold that darkens the lines of grout between your tiles is a bad idea. Mold, particularly the dreaded black mold, is a type of fungus that thrives in moist, warm environments.
Grout sealer can help prevent mold growth to some extent by reducing the porosity of the grout and making it less susceptible to moisture absorption.
Check the color and condition in some of the higher-traffic areas of the room. If you notice any chipping or cracking in the grout, it won't respond well to cleaning and will most likely just break apart if you try to clean it with any kind of physical force.
Hydrogen peroxide is another safe option when removing mold from your tile grout. Hydrogen peroxide is a natural cleaning agent with anti-fungal properties.
Hydrogen peroxide, commonly used to disinfect wounds, is active against a wide variety of micro-organisms including mold. It acts by releasing oxygen at a rapid rate, which kills mold by oxidizing the surface and breaking down proteins and DNA.
Vinegar is good at killing plant matter, that much is true. But it can rarely penetrate deeply enough to kill fungi like mold down to the root. That's why it usually isn't truly effective in cleaning black mold, green mold, and most kinds of common house molds.
Bleach. The most common method of removing mould from grout is through the use of regular domestic bleach. Ensuring you're wearing a mask to keep you from inhaling any toxic fumes, this method involves scrubbing bleach directly onto mouldy areas of your grouting using a stiff bristle brush or old toothbrush.
If your bathroom or shower grout is extremely mouldy and discoloured beyond repair, then your best option would be to remove all of the old grout and spray the tile joints with either vinegar or methylated spirits to kill any mould spores.
Chemical cleaners, such as, Tilex, Soft Scrub, Scrubbing Bubbles, or ammonia products will nearly always result in your tile surfaces' grout becoming very discolored.
Final Verdict. Our favorite grout cleaner is the Black Diamond Ultimate Grout Cleaner Spray for Tile with Brush. It can be used to lift various household messes and stains on many surface types. We also love that it comes with a firm-bristled scrub brush.
If you're a die-hard DIYer, using Dawn dish soap alone can be a safer option for mild cleaning. Dilute a small amount of Dawn in warm water, scrub the grout with a soft brush, and rinse thoroughly. However, this method is less effective for tackling stubborn stains or deep-seated grime.