Your grey grout is turning white because of efflorescence (mineral salts migrating with moisture), latex leaching (excess water during cleanup), or sometimes hard water deposits, all caused by moisture interacting with porous grout, leading to a powdery or hard white residue as it dries. Identifying if it's powdery (efflorescence/latex) or hard (hard water/latex) helps, but the core issue is moisture, often from excessive water during installation, poor drainage, or water getting behind the tiles.
Make a paste out of hydrogen peroxide and baking soda. Put it on the grout and let it sit for awhile, then scrub with a toothbrush or something similar. It worked amazingly on my white grout!
Efflorescence is a white deposit (usually calcium carbonate) that develops on the surface of grout and/or tiles as they dry out. It happens when soluble, naturally occurring mineral salts contained in Portland cement, or materials used in conjunction with it, rise to the surface.
Use Baking Soda And Vinegar
Wet the Area: Dampen the affected area with water to loosen the efflorescence. Apply Grout Cleaner: Follow the manufacturer's instructions for your chosen grout cleaner. Apply it to the affected area and let it sit for the recommended time. Scrub: Use the grout brush to scrub the area gently.
We know that efflorescence is a clear indicator of moisture issues within a structure. Its presence can signify past leakage, even when the surface appears dry. Addressing efflorescence build-up and active leaks can be crucial for the longevity of concrete structures.
Luigi's Answer: Under certain circumstances, a white powder can form on grout, especially on floor tiles. This is a natural phenomenon known as efflorescence. It is due to soluble salts rising to the surface of a cement based product.
You generally should not grout directly over old grout for longevity and adhesion, as it often leads to cracking and peeling; instead, you must first remove a significant portion (at least 2mm) of the old grout, thoroughly clean the area, and then apply the new grout to ensure proper bonding and a lasting finish. Special rejuvenation grouts or epoxy grouts might require less removal, but scraping out most of the old material is the best practice for standard grout.
Clean's best way to clean grout is with the Mr. Clean Magic Eraser Bath with Gain Original Scent. Bursting with the fresh scent of Febreze® Meadows & Rain, it's powerful enough to knock out even the most-stubborn buildup on grout throughout your bathroom.
4 Easy Ways To Remove Grout Haze
Efflorescence is often seen as a white fluffy deposit of salt crystals on cementitious (e.g. masonry) wall surfaces. Efflorescence depends on the presence of salt and moisture, and the growth of crystals will continue as long as both are present.
Compared to bleach or vinegar, hydrogen peroxide is less likely to damage grout or nearby tile, mainly when diluted or used in a paste.
It is a neutral cleaner. This means it is safe to use on most surfaces in your bathroom, including grout. Methylated spirits is safe to use on glass, sinks, chrome taps, ceramic, stone, marble and grout.
Bleach, ammonia, and cleaners with these harsh chemicals added in can cause grout to yellow, fade, or become discolored. They can also degrade the grout and cause it to erode over time.
Bleach is a powerful last-resort option for mould and mildew stains. However, it should only be used on white grout as it can cause discolouration.
Regrouting is the best option when tiles and grout begin to show signs of discoloration or the stains are so deep that they cannot be removed. As grout ages, it naturally deviates from its original color. If the white grout turns yellow or is covered with stains, you must regrout very soon.
While grout pens are not a permanent solution to some grout issues, they're still an affordable and easy way to help you transform your home. Just be sure that you choose a grout pen in a color that works for your style, the room itself, and the tile.
Regrouting tiles is a straightforward job that most confident DIYers can tackle themselves. Take your time when removing the old grout to avoid chipping or damaging your tiles.
If the while condition is actually efflorescence then it should be able to be removed with a slightly acidic solution like vinegar, which should only be used as a test to verify it is efflorescence. If it is efflorescence, then purchase a tile cleaner that is made for removing efflorescence.
Although unsightly, the mineral deposits can be safely removed by following a few simple steps. In most instances, efflorescence can be removed and future growth inhibited with Aqua Mix® Eff-Ex® over unsealed cement grout. Heavy contamination of efflorescence salts may require a mild acid wash.
In many instances when the grout has become permanently stained and no amount of cleaning can bring back the original uniform clean look of the grout. In these cases, it is best to apply Universeal Grout Rescue Colour & Seal to restore the grout to a permanently sealed even coloured finish.
Here's the secret: magic erasers! I know there are grout pens out there that whiten grout, but that's just paint. I want to actually clean my grout. Magic erasers get the job done, and they do it quickly and relatively painlessly.