Chlorine bleach is the most commonly used cleaning agent when it comes to DIY mold grout removal. It works well and not only kills the mold spores, but also disinfects the area and removes the buildup of soap residue from the tiles and grout.
Use a Bleach Solution
Prepare a one-part bleach and four-part water solution in a spray bottle. Spray the solution on the moldy grout and let it sit for about 30 minutes. Use a rigid toothbrush and do some vigorous scrubbing to make sure you have covered all the areas.
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.
Grout that hasn't been sealed, needs to be resealed, or is in poor shape should not be cleaned with vinegar. The vinegar penetrates into the pores of the grout, further weakening the material. Over time, vinegar will deteriorate the condition of the grout by etching or wearing it away.
We highly advise against using ammonia or bleach to clean any grout. Cleaning solutions that contain bleach or ammonia will not only work to erode your grout over time, they will cause your grout to become even dirtier by leaving a film behind, which attracts dirt.
You can also use white vinegar for chemical-free grout cleaning. Simply pour vinegar from the bottle into the cap and pour it over the dirty grout lines. Allow the lemon juice or vinegar to sit for 10 to 15 minutes. Then, scrub with a small brush or old toothbrush.
Pour enough undiluted white vinegar into the empty spray bottle to cover the area of mold growth. Spray the mold directly, fully saturating it with the vinegar, and allow the vinegar to sit for at least an hour. Don't be tempted to scrub or rinse; the mold needs time to completely absorb the vinegar.
Also, you risk causing damage to the area beneath the mold when you leave the vinegar to sit on it for too long. So when it comes to removing mold with vinegar, it's best to avoid leaving it overnight and stick with the 30 minutes to 1 hour sitting time.
Discolorations in your tile and grout aren't just unsightly—sometimes they are downright dangerous. The dark spots on grout are most likely the result of mold, mildew or plain old dirt buildup. It is important to determine what you're dealing with first, so you can wipe it out with the appropriate treatment plan.
In some instances, grout can even become permanently stained and sometimes all your daily cleaning will not make a difference. Tile grout can also turn black due to mold. Mold usually develops in areas where there is high humidity or in areas with moisture.
The most common culprit is leakages. The perfect environment for mold to grow can be created by even a small leak from cracked tiles or loose grout. Other causes of black mold in showers include: Poor ventilation: If your bathroom is not well-ventilated, the moist air can cause mold to grow.
Try a baking soda paste.
Apply the paste to the grout, and let it sit for one to two hours. Spray with plain water, then scrub the grout again. Alternately, make a paste from two parts baking soda to one part hydrogen peroxide. Let the paste sit on the grout for several minutes before scrubbing it and rinsing it clean.
Avoid Vinegar and Baking Soda
Vinegar and other acids are also a bad idea for stone tile because the acid can etch the stone. Another widely praised household cleaner, baking soda, is alkaline (not acid), but it is not very effective as a grout cleaner.
What's the best homemade grout and tile cleaner? Mix together 1/2 cup of baking soda, 1/4 cup of hydrogen peroxide, and 1 tsp dish soap. Apply cleaning mixture onto the grout, wait 5-10 minutes, scrub, sweep up the excess baking soda, and rinse.
Baking soda is a safe deodorizer, whitener, and household cleaner—and it's an effective natural grout cleaner.
First, wash your tiles and grout with sugar soap using a toothbrush and scrubbing brush. We used Selley's Sugar Soap concentrate for this, mixed with warm water in a bucket – it works a treat. Use your toothbrush, scrubbing brush and some elbow grease to scrub the grout and give it a good going-over.
Can CLR Brilliant Bath be used on colored grout? No. It is only safe to use on white grout. If used on colored grout it will lighten the grout color over time or discolor.