A brief guide on how to clean flooring grout lines.

What Are Grout Lines For?

Grout lines serve many functions. First of all, by connecting the individual tiles, they seal the installed surface. Since the grout is more elastic than tiles, which are extremely rigid, grout lines accommodate small expansions in the substrate caused by fluctuations in temperature, thus preventing detachment or cracking if the subfloor flexes. Furthermore, grout conceals minor and occasional irregularities in the dimensions of the tiles themselves, which is especially important in the case of unrectified formats.

Finally, because grout lines create a minimal gap of just a few millimetres between the tiles, they help reduce any unevenness that, for a variety of reasons, there may be between one tile and the next. This is more noticeable in the case of rectified formats. Obviously, these discrepancies are nearly imperceptible if the ceramic material chosen is of high quality and if its installation is handled by experienced professionals. In any case, a grout line of 2 mm will do the trick.

CEMENT GROUT OR EPOXY GROUT?

There are essentially two main families of materials that can be used for filling grout lines: cement-based mortars and epoxy resins. Cementitious grouts have been used in residential settings, on both floors and walls, for a long time. The most advanced versions are scratch-resistant and even water-repellent, qualities not typically associated with cement. When of high quality, these grouts also offer outstanding performance in terms of anti-efflorescence, mould resistance, low VOC (volatile organic compound) emissions, and durability of colour over time.

Epoxy grouts demonstrate remarkable elasticity, excellent water repellence, and superior resistance to abrasions, chemicals, and mechanical stress. They’re also stain-resistant, immune to efflorescence, and resistant to mould and bacteria. Thanks to these qualities, they’re primarily used for flooring in public spaces, which are typically subject to heavy foot traffic and fluctuations in temperature and humidity that can compromise the level of hygiene.

Due to these characteristics, epoxy grout tends to cost more than cementitious grout. However, now that over-sized rectified formats and ultra-thin tiles are being used in residential settings as well, it may be worth considering the use of epoxy filler. In fact, the amount of grout required will actually be reduced as it depends on the size of the tile as well as the width and depth of the joint.

Why Do Grout Lines Get Darker?

Grout lines get dirty more easily than tiles for various reasons. The main ones are:

Type of grout line. Cementitious grout is more prone to staining than epoxy grout. The latter is, in fact, inherently waterproof. This non-porous quality also makes it less likely to trap dirt. In contrast, cement, due to its physical and chemical structure, is a porous material. As a result, it tends to absorb liquids and trap dirt more easily.

Accumulation of dirt. Grout lines are slightly recessed compared to the tiled surface. This means that brooms and vacuum cleaners aren’t always as effective at removing everyday dust and dirt from the grout as they are at removing it from the tiles. Over time, these contaminants accumulate, darkening the grout lines.

Humidity. Especially in the bathroom and the kitchen, humidity promotes the growth of moulds and fungi which, in addition to causing unpleasant odours, also darken the grout lines and compromise the overall hygiene of the ceramic surface.

Aggressive detergents. Sometimes the use of overly aggressive detergents can lead to the darkening of grout lines. It may seem paradoxical but, because these products can damage the surface of the grout lines, they end up making them more porous and, consequently, easier to stain.

How to Clean Grout Lines: The Most Effective Products

Now let’s look at the most practical and effective solutions for removing dirt from tile grout, making it once again beautiful and, above all, hygienic. It’s not always easy to find a product specifically designed for cleaning tile grout in stores, though foam bleach can be a good option. However, excellent results can also be achieved with less toxic products commonly found in households.

Baking soda. Cleaning grout lines on the floor with baking soda and water is quick and simple. These should be mixed in a one-to-two ratio to create a paste that can be applied to the darkened grout lines. Allow it to sit for about twenty minutes, then wipe the grout with a damp cloth until the mixture is completely removed. Obviously, this method is equally effective for vertical grout lines, especially in the kitchen, where they tend to turn yellow due to grease vapour from cooking.

White wine vinegar. Its antifungal, antibacterial, and deodorising properties make it an ideal product for cleaning grout lines. It can be poured directly onto the grout or sprayed on with a spray bottle after diluting it with warm water. Let it sit for a few minutes, then wipe it away with a warm damp cloth.

Hydrogen peroxide. Using hydrogen peroxide to clean grout lines is another valid option. A 10-volume dilution, once used for disinfecting wounds, is sufficient, though higher concentrations are more effective. Spray it onto the grout and let it sit for about twenty minutes, then scrub the grout vigorously and rinse thoroughly.

Grout can also be effectively cleaned with steam, even if you’ve chosen wood-look porcelain stoneware. Steam is an excellent solution because it doesn’t use any chemicals, just heat. The temperature reached by the steamer (at least 100°C) is able to dissolve even the most stubborn stains. Simply point the jet of steam at the grout to quickly remove dirt, obviously taking care not to burn yourself. Afterward, the floor should be thoroughly washed, as we recommend in this article dedicated to cleaning porcelain stoneware.

Brushes and Tools for Refreshing Grout Lines

As we've seen, care and attention are the best “products” for cleaning the grout lines of a stoneware floor. But can a brush also be used to help clean grout? Absolutely! Laundry brushes (preferably with a handle) and toothbrushes are perfect tools because they’re not overly aggressive, even when used vigorously. It's important to never use sandpaper or stiff scrapers (made of plastic or, worse, metal), as they could damage the filler — especially if it's cement-based — and also ruin the ceramic, particularly given the narrow width of the grout lines.

In the case of particularly stubborn stains, or for more information on cleaning grout lines, you can always contact our technicians. Simply fill out the specific contact form, making sure to select “cleaning and maintenance” from among the reasons for your request.