How to Clean Tile Grout: Everything You Need to Know

Keeping grout in good condition is essential for the aesthetics, hygiene, and durability of a ceramic floor. With a few tricks and the right products, you can renew tile grout easily, making it look bright and clean again, and prevent it from darkening. But let’s take a step back: what is grout? What is it for? What material is it made of?

Tile grout: what it is and which filling materials are used

Grout is the space that separates two adjacent tiles. It is not an aesthetic element but a functional one. In fact, it is an indispensable technical requirement. Installation without grout, according to the international standard UNI EN ISO 11493, is not allowed. This is because tile grout helps compensate for thermal expansion and any slight dimensional imperfections. It also allows you to minimize small unevenness between tiles that may depend on installation.

The width of the grout line depends on several factors, including the type of tile edge used. As explained in this article, for tiles with rectified edges, narrower joints are used, but never less than 2 mm. For tiles with non-rectified edges, grout lines between 3 and 6 mm must be considered.

The material used to fill these gaps comes in two types:

• Cementitious grout, made mainly of cement, very fine sand, and some additives, including colorants that determine the final shade. Cementitious grout is mixed with water before application;
• Epoxy grout: a two-component compound based on epoxy resins, to which a hardener is added.

Cementitious grout or epoxy grout: features and benefits

Both solutions offer advantages, but they are intended for different areas of use:

• Cementitious grout: the most common choice for domestic spaces. However, since it is more porous, it can absorb dirt and moisture, and more easily become a breeding ground for mold and mildew. Cementitious grout is, however, easier to apply and more economical than epoxy grout;
• Epoxy grout: thanks to its resin-based composition, it has a smooth and minimally porous finish and is water-repellent. It is impermeable, stain-resistant, and resistant to chemicals. In the home, it is perfect for kitchens or bathrooms. More generally, it is preferred over cementitious grout in many public settings, where floors are subject to heavy traffic and exposed to spills of drinks, detergents, or chemicals, or to falling food. Its application and, above all, the timely and thorough removal of excess after filling the joint are delicate operations that must be carried out by skilled installers.

More generally, all installation phases should be entrusted to professionals, otherwise the result may be compromised by technical or aesthetic defects. In particular, imperfect post-installation cleaning of a floor, even if perfectly installed, can make future cleaning more difficult.

Why grout darkens and how to prevent this problem

Cleaning porcelain stoneware floor grout regularly is important for three reasons:

1. Hygiene: since grout is porous (especially cementitious grout), it tends to absorb dirt, dust, mold, and bacteria. Regular cleaning prevents harmful build-up that could affect health;
2. Aesthetics: dark or stained grout undermines the overall appearance of the floor, even if the tiles are well maintained. On the other hand, light and clean grout enhances the entire surface;
3. Durability: over time, encrusted dirt can damage the filling material, causing cracks and infiltrations. Proper maintenance extends the lifespan of the floor.

Before looking at how to clean grout, let’s ask ourselves: why does grout darken over time? Here are the main causes:

• Dirt and dust that accumulate over time: grout lines are always slightly recessed compared to the tile surface, creating small grooves (even if only a few tenths of a millimeter deep) where dirt tends to settle;
• Humidity and poor ventilation can promote the growth of mold and mildew, which darken grout color, may cause bad odors, and make surfaces less hygienic;
• Harsh or unsuitable detergents can damage the filling material and make it more porous, thus more receptive to dirt.

Here are some useful tips to prevent these issues and clean floor grout effectively:

• Use neutral detergents specifically designed for porcelain stoneware;
• Clean it regularly with suitable tools;
• Avoid oily products or undiluted bleach: they can alter grout lines;
• In humid environments (such as the shower), dry ceramic surfaces after use and ventilate regularly.

Techniques and products for cleaning tile grout

When dirt builds up, it is important to know how to clean porcelain stoneware grout effectively and safely. Here are some techniques to whiten tile grout:

• Using a specific detergent gives you the confidence of having the best product for cleaning grout, designed specifically to remove dirt without damaging either the grout or the porcelain stoneware. These are mostly very specific products but easily available online. On the other hand, foam bleach is available in any supermarket, with a consistency that allows it to stay on the grout long enough to act. Before using any cleaner, you should carefully read the instructions and safety warnings; it is also always advisable to test the product on a less visible grout section;
• Use baking soda mixed with a little water until you obtain a paste, then apply it to the grout with an old toothbrush. Baking soda whitens and removes encrustations; it should be left to act for about ten minutes, then removed. At that point, the grout should be rinsed thoroughly;
• Dilute white vinegar in water and spray the solution onto the grout. Leave it to act for a few minutes, then rinse thoroughly. Vinegar is known for its antifungal, deodorizing, and antibacterial properties;
• Use hydrogen peroxide to clean grout: in the 10-volume version (i.e., diluted to 3%), hydrogen peroxide was once used as a medical disinfectant. In this dilution, it is useful as a product to whiten tile grout, applied in the same way as the vinegar and water mix.

Finally, remember that it is always possible to clean porcelain stoneware grout with steam. The heat of the steam from the steam cleaner does not damage the tile surface in the slightest, since it was fired at as much as 1200 °C! However, it effectively removes dirt from the grout without the need for detergents or chemicals. Steam is also an ideal technique to clean shower grout.

Brushes and tools for cleaning floor grout

The choice of cleaning tools is as important as that of the detergent. For effective cleaning, you can use:

• a plastic-bristle brush with a comfortable handle that allows you to apply some pressure;
• a toothbrush for narrower grout lines and hard-to-reach areas;
• a steam cleaner for deeper and more eco-friendly cleaning.

It is important not to use excessively abrasive sponges, metal scouring pads, or scrapers—whether hard plastic or metal. These tools can damage the grout filling material and even scratch ceramic surfaces, especially if, like many marble-effect tiles, they have a glossy finish.

For a complete guide to maintaining porcelain stoneware, we recommend referring to the manufacturer’s cleaning manual (here, for example, you can find Panaria’s). Often, you will also find useful instructions for grout maintenance.