Efficient use and reuse of raw materials and end product
In the production and application of terracotta, energy sources and the waste generated during the various stages of the manufacturing process and subsequent installation of the tiles are carefully handled. The surplus of clay that is released after pressing into molds is immediately reused in the production process.
Tiles that are no longer marketable are often crushed into gravel in various sizes and offered to the market as such. Terracotta tiles with a glaze layer, as is the case with wall tiles, can be “tumbled” with a certain grinding technique so that they can be used as mosaic stones.
The cutting waste that is released when tiles are laid appropriately can be recycled inexpensively. Most cutting waste comes from tiles in different sizes, which are specially made to lay in a pattern shape, such as the “Romanesque” laying pattern.
The productionproces; energy efficient but labour-intensive
In general, the producers of terracotta all have their own clay mine next to the production site. There are therefore no transport costs associated with transporting the raw materials to the processing location, so this does not burden the environment.
In the processing location, the clay, which contains minerals such as salt crystals that determine the structure of the tile after firing, is mixed with water. Although a number of producers also produce mechanically, most often further process the clay in a traditional way, a labour-intensive processing process that takes a relatively long processing time compared to the machine-produced terracotta tiles; in mechanical processing, the clay is pressed into molds via transport systems.
In the manual, traditional process, (walnut) wooden molds are used. Large pottery, such as terracotta pottery, is made entirely by hand without using moulds. The layers of clay from which the pot is built are rolled one by one and provided with any decorations by hand.
Prior to firing, the mold-pressed clay tiles are laid flat on the ground in an open space to complete the natural drying cycle. Therefore, no additional energy sources are used to dry the tiles. Due to the lower humidity, the drying process is faster in summer than in winter.
After the drying period, the tiles are baked for six days at a temperature slowly rising to approx. 1040°C. The firing takes place in energy-efficient gas ovens and, where it concerns a handmade tile where it is important that the tile shows the color variations characteristic of terracotta as a result of firing, in (often olive-tree) wood-fired ovens. The shades are the result of where the tile was placed in the wood oven. Because the temperature in the upper parts of the oven is higher than in the lower parts, the flames along each individual tile form a natural cooking pattern. This vibrant pattern, which is different in every tile, creates a warm and welcoming atmosphere once the tiles are installed.
After firing, the tiles are cooled to ambient temperature, after which they are removed from the oven, checked and carefully selected. Tiles that do not meet the quality requirements are crushed and reused as raw material.
Finally, approved tiles are dipped in a water bath to break down the salty minerals still present in the tile, which can be the cause of cracks in the tile if not cooled enough.
As a result of the high quality of the clay and the manufacturing process used, the tiles are frost resistant to -45°C, which means that they can also be used in cold continental climates.
The installation of a terracotta floor: natural material, environmentally conscious grout and environment-friendly installation
Unlike a floor made of ceramic tiles, which are factory-made from cement with an even thickness, laying a floor made of handmade terracotta requires professional expertise. Laying such a floor is fundamentally different from laying a floor made of other materials such as cement and plastic tiles or wood.
The handmade terracotta tile, which can vary in thickness due to the hand-shaping of the material, is made of clay, a natural and naturally porous material that absorbs liquids when applied ‘raw’ to the adhesive layer. For this reason, terracotta tiles must be washed with water before installation and a special flexible adhesive must be used. The use of a trowel of the correct size to absorb the thicknesses is necessary for an even and correct leveling of the floor.
Pre-treating the tile with a wax product and using a grout that meets special requirements prevents the tile from being damaged by the grout.
The choice of grout when installing tiles is worth considering in an environmentally conscious sense. A grout containing as few coloring agents as possible appears to be a ‘better’ grout. In general, a narrow joint between the tiles is more durable than a wide one. The reason for this is that the grout is softer and more fragile than the tiles, which means that it can ‘silt up’ over time. Due to this characteristic, wide joints increase the risk of damage, which would mean that tiles would have to be replaced. Although more tiles are needed with a narrow joint than with a wide joint, the knife cuts both ways when it comes to choosing a narrow joint; terracotta tiles are made of a natural material that is energy efficient and the narrow joint prevents damage and replacement of the tiles.
In addition to choosing the right grout and using a ‘clean’ grout, removing the cement film by cleaning with just water is generally sufficient. Stains that are more difficult to remove can be treated with specific products commercially available for that purpose. It is recommended to have the floor impregnated with oil by the manufacturer beforehand, so that no liquid stains, such as from wine, can penetrate the tile. If desired, the oil can be provided with a coloring agent to give the natural color of the floor more ‘depth’. If necessary, the floor can be treated with a wax product.
Although laying a tile floor seems simpler than it is, with a ‘living’ terracotta floor it is recommended to use the expertise of a professional tiler who has experience in laying terracotta tiles.
Renewal of old, dirty or damaged terracotta floors
Terracotta floors that are soiled or damaged do not need to be replaced in their entirety to last a lifetime.
A dirty floor can be professionally cleaned and broken tiles can be replaced, making them look like new again.