To touch up shower grout, first clean and remove loose old grout with a grout saw or utility knife, vacuum the dust, then apply new grout (premixed or mixed from powder) with a rubber float, pressing it in diagonally. Wipe off excess with a damp sponge, let it set, and buff away haze with a dry cloth, then seal it after it fully cures (24-72 hours).
You generally should not put new grout directly over old, crumbling, or moldy grout, as it won't bond well and the underlying issues will return; however, you can apply new grout over existing grout if you first remove the top layer (about 2mm deep), thoroughly clean and dry the area, and use a specialized "rejuvenation" grout or properly prepare the surface for a strong bond, which creates a time-saving shortcut but removing most or all old grout is always the best for longevity.
For small missing grout areas, remove loose grout with a grout saw or scraper. Clean the gaps thoroughly and let dry. Use a grout-specific caulk (silicone-based) only for corners or edges, not flat grout lines. For larger gaps, regrouting is necessary: apply new grout with a float, press firmly, then wipe excess.
It'll also last longer on the bathroom or kitchen tile floor than in the shower for obvious reasons. So using a grout pen is great way to refresh the color of grout, or even change it from say white to black, but it's not a permanent fix. Granted you can paint over the grout again in few months.
Waterproof and Anti-Mould
It is also waterproof and dries after just 60 minutes, making it ideal for showers.
Using the pen
It's ridiculously easy. Paint over the offending, grubby grout with the pen. That's it. The ink will cover the muck and restore the grout to its sparkling former glory.
To repair cracks, use a caulking gun and silicone caulk designed for wet areas. Fill cracks flush with the tile surface or slightly below. For missing grout, use a grout saw or similar tool to remove any loose debris from joints.
If you are wondering how long you should wait between grout sealing on your high-traffic floors or frequently-used showers, the answer is at least once per year. However, The Grout Medic recommends sealing those areas every six months.
The Pink Stuff
Simply rub and scrub, and then rinse with hot water. As a mildly abrasive cleaner, the paste has a little grit to it, which helps scrub away dirt and debris from grout and surfaces.
4 of the Most Common Regrouting Mistakes
Can you grout over grout? It is highly recommended to remove your old and damaged grout before applying new grout.
Since grout is porous, it crumbles over time with normal wear. Using grout to fill in cracks will restore it beautifully, and you can make spot repairs as needed.
If the tile has small chips, use epoxy resin or tile repair adhesive to fill in the missing pieces.
Signs to Look Out For
You might notice discolouration, hairline cracks, or sections that crumble when touched. In severe cases, whole pieces of grout may be missing, leaving a visible gap between tiles. You may also see water pooling at the edges of your shower or notice damp spots on walls outside the shower area.
The 1/3 rule for tile is a layout technique for long rectangular tiles (like wood-look planks) that recommends staggering joints by one-third of the tile's length, not the traditional 50%, to minimize lippage (uneven tile edges) caused by natural tile bowing, creating a smoother, safer, and more visually harmonious floor or wall. Instead of a standard brick-like pattern, it creates a diagonal or "stair-step" grout line, which looks more natural and helps hide slight height variations between tiles, making the surface feel flatter and more professional, especially under raking light.
Benefits of Regular Grout Sealing
Prevents Stains and Discoloration: Sealed grout resists absorption of spills and stains, keeping your shower looking clean and new. Inhibits Mould and Mildew Growth: A proper seal prevents moisture from penetrating the grout, reducing the risk of mould and mildew formation.
Install professional-looking tiles by learning from these common grouting mistakes.
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.
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.
Since paint is not formulated to be applied to grout, it will not produce a great result. It will sit on top of the surface of your grout lines, and it will not last. Even if it looks okay in the beginning, it will end badly in a short amount of time.
Fixing grout and re-grouting tile isn't complicated, but you need to match the color of your grout first. Get sample chips from Lowe's and find the closest color match. If the original grout color is lighter than the color you chose from the chips, lighten the new grout by adding more water when you mix it.
Yes, grout pens are good for an affordable cosmetic fix, making tiles look new by covering stains and discoloration easily, but they are generally not a permanent solution, lasting 6-12 months in wet areas before needing touch-ups, with performance depending on preparation and usage (wall vs. floor). They work best for refreshing grout, changing color, and tackling surface issues rather than deep-set mold or damage, and while some report excellent durability, others find the nib wears down or paint peels without proper prep.