History of the hydraulic tile  

In the most modern kitchens or in the smallest bathrooms, we can find a material that is repeated in all of them; a material with unique characteristics that bring color and design to any room: CEMENT TILES, also known as hydraulic tiles or hydraulic mosaic.

Born in France at the end of the 19th century, these small pieces of cladding became famous not only for their infinitely creative designs and colors, but also because in their manufacture the cooking is dispensed with, as in the case of ceramic tiles.

The technique consisted in the pouring of a mixture, based on cement, sand and pigments, on a mold or a trepan that was placed under a hydraulic press that compressed it. However, all this would not have been possible without the invention of modern cement: Portland cement. Named after the famous Dorsey island stone for its similarities, this compositionally enhanced material was patented in England by Joseph Aspdinen 1842, offering more resistance to moisture and more profitability.

In this way, with pieces of approximately two centimeters in thickness, a material was obtained that could replace the ceramic-stoneware with a lower manufacturing cost. In addition, its almost manual manufacturing created equal pieces, but different. Although we associate them with the pavements of modernist vernacular architecture, mosaics or hydraulic cement tiles are still used today for their economy, ease of placement, designs, features and maintenance. In this book of ideas we immerse ourselves today in the world of cement tiles, explaining their manufacture and materials, their characteristics, their placement and, finally, their care.

Materials

The Mosaic Tile or hydraulic cement tile is a piece of geometric shape with sharp edges or bevelled used for the coating. It can be placed on virtually any flat surface in the home: floors, walls, stairs, ceilings, bathrooms, decks, swimming pools or facades. These are composed of three different layers:

1. Top side: this visible layer is made of a fluid paste of white Portland cement, very fine sand and dye or pigments. Its thickness is approximately 4 mm and it is spread by hand on the steel mold.

2. Intermediate layer: called brasage, this layer is composed of a mixture of sand and dry Portland cement, whose function is to absorb water from the first layer. Its thickness approaches 1 centimeter.

3. Base layer: called gros, this layer constitutes the back of the tile and its mixture is similar to that of the intermediate layer, but of worse quality. Its rough surface ensures the adherence of the tiles to the gripping mortar.

Manufacturing   

To make the three layers that we have discussed in the previous image, we will need different tools. In the first place, a mold or a trepan that integrates some spacers fitted inside a frame. Since the first of the layers is the one that contains the colors and drawings, it is the most difficult to elaborate and, consequently, the one that costs the most money. To ensure that the colors do not mix, these climbers had separators or dividers, allowing drawings of the most varied.        

Once this first layer is placed, the separators are removed and the second layer is added and then the third layer in the rest of the mold. When we have already placed the entire mixture, it is necessary to apply the pressure by means of a hydraulic press. The purpose of this is to unite all the strata and compact them to obtain the most consistent pieces possible. The press must contain, at least, 120 kilograms per square centimeter.

Once the weight is applied, the mold is removed and the plate is allowed to dry. During the following days, it is necessary to spray the plates with water to ensure the cure of the cement. They are left to dry a few more days and we already have our tiles.  

Unlike stoneware tiles, these pieces are not glazed. Their characteristics vary according to the proportions of their materials. However, we must emphasize its low water absorption, its bending capacity and its resistance to wear. On the other hand, the colors and drawings are infinite, so these plates fit in very varied environments always creating a spectacular effect.

Tiling and Placement

  First of all, it is necessary to say that the tiles can be placed both indoors and outdoors. However, depending on the environment we will have to take specific precautions in its application.

If we have decided to place them in an interior space, a penetrating sealer and / or waxing is recommended to protect them from any water, grease or oil stain. If on the contrary, our intention is to place them in an external environment

we will have to protect the material from the rays of the sun with a penetrating sealer that helps to preserve its natural color and shine.

1. We must ensure that the surface on which we are going to place the tiles, whether horizontal or vertical, is stable, is well leveled and, above all, completely dry.

2. Once our surface has been prepared, we will apply gripping mortar with a rake of coarse teeth both on the surface of the wall or pavement, and on the back of the tile. This will improve their grip and prevent them from peeling off in the future. This step will be fundamental to perform it with care since the adherence of the pieces will depend on it.

3. We will place the tiles, one by one, while leveling them manually, (we should never use hammers). Once placed on the surface, we will clean the fine layer of dust from the surfaces with abundant water.

4. To fill the joints, we should never use cement tinted joint because they can irreversibly dye our pieces. For this step, we will use a spatula and will be very careful not to scratch the pieces. Next, we will clean the excess mortar with a damp cloth. This step will have to be carried out immediately afterwards to prevent the mortar from drying on the surface.

The use of acidic materials to clean it is absolutely forbidden. 6. With the five steps above we will have our surface covered with tiles. Now let's dry two or three days. Once the pieces are fixed, we will clean the surface with a neutral detergent and if we want to wax the surface a white pad.

Despite its great durability, beware! We should not leave water drying on the surface and we should help ourselves with a dry cloth to preserve its beauty and natural shine.

Maintenance  

In wet areas of a house, from a bathroom to a pool, we must also protect them with a penetrating sealer to ensure its impermeability and, subsequently, an acrylic sealer.

After these small tips, we will proceed to explain the step-by-step placement procedure in case someone is interested in doing it himself.

In any case, we always recommend the help of a professional to make sure that the placement is perfect and we obtain high quality results: Regarding the maintenance and care of this material, we recommend taking special care with the grit, because on their surfaces they can be abrasive. Therefore, in the case of pavements, we must clean them daily, eliminating any coarse particles that can irreversibly scratch our pavement.

In addition to dry cleaning by brooms, dusters or vacuum cleaners, we can use detergents or neutral soaps trying to dry the surface once cleaned with cloths or newspaper. If we want to give back some of its natural shine, we can make use of a periodic waxing with a polish and a cloth.

One of the advantages of mosaic or cement tile based coatings is that most stains can be removed easily. In this way, to clean it we will only need a soap and a cloth. However, if there is a stain that does not come out with water or detergent or soap, there is a remedy that we can use, but with which we will have to be especially careful: oxalic acid!

Although we have commented before that it is preferable not to use acids for the cleaning of this type of material, if necessary we can do it, but under these indications: first, we should protect ourselves with gloves and even eye protectors the most sensitive. Next, we moisten the stained area and rub in circular motions using a pad and oxalic acid crystals until the stain disappears completely. We will eliminate any residue, rinse the area and let it dry.

As we mentioned in the introduction, this type of coating became famous in the modernist period, where pavements with very colorful drawings and incredible compositions were sought. Later, it was losing importance until 1950 where its manufacture fell considerably and was replaced by lighter elements.

At present, although to a lesser extent than before, these small pieces continue to be used to create environments linked to tradition, but without abandoning the design, warm environments, full of creativity where the walls or floors become the protagonists of the spaces and of the most worthy praises.