Hydraulic Tiles: Artisan Manufacturing and Custom Design

Written by Materials | Translated by José Tomás Franco
Published on September 24, 2020

Hydraulic tiles are tiles produced entirely by hand with cement-based raw materials. Created in the mid-1800s in Spain, and widely used in Europe and America, it is a versatile option that can not only be applied in public areas, such as squares and sidewalks, but also interiors, including floors, walls, and furniture. Their versatility stems from the fact that they are highly customizable, from their colors and patterns to their geometry and dimensions. Read below a mostly technical explanation of these tiles, their manufacture, and their installation.

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Hydraulic Tiles: Artisan Manufacturing and Custom Design - Image 21 of 22 — Apartamento Joaquim Antunes 149 / Metro Arquitetos Associados. Image © Ilana Bessler

Features and Benefits

Hardness: has a high resistance to impact.
Diversity: gives designers the option to use different graphic patterns, allowing the customization of spaces and the generation of complex compositions with other materials. As they are unique pieces, it is also possible to customize their colors, which can remain intact for years if they are properly waterproofed.

Uniqueness: the same design, depending on its position and the chosen colors, will produce a completely different and unique geometric effect. An important detail about this feature is that hydraulic tiles will always have some minor imperfections and variations in their tones.
Ease of maintenance: for routine maintenance, it is recommended to apply colorless liquid wax with a squeegee every 15 days or when the tiles begin to lose shine. For cleaning, it is recommended to use mild soap and water. The wax preserves the resin, so it is important to apply it regularly.
Versatility: the tiles can function as a covering for floors, walls, or even furniture, both indoors and outdoors, and in public or private places.

Fabrication process

The hydraulic tiles are completely handmade and manufactured individually by artisans using a meticulous technique that extends from the preparation of the paint to the final drying of the product. Through each step, the artisans employ the necessary care to ensure the quality of each tile. The process consists of eight steps:

A bronze mold is produced with the desired pattern. The mold fits into an outer iron frame that follows the shape of the tile edge, with the most common measurement of 8"x 8".
Each part of the bronze mold is filled with a pigmented liquid mixture (of the color specified in each project). This mix is made with iron oxide, marble dust, and white cement.
The bronze mold is then removed and the colored surface is covered with a dry mix and immediately after with a wet mix.
The tile is compressed in a hydraulic press (giving the tile its name).
Now the mosaic can be removed from the mold, but with great care, because it is not fully cured yet.
The piece must rest for 24 hours and remain submerged in water for approximately 8 hours.
Afterward, the tiles are stored for 4 weeks in the shade. This step is important for the crystallization of the cement.
The tiles are ready to be applied on site.

Recommendations for installation

When handling the tiles before installation, they should always be placed face to face, to avoid scratching.
Hydraulic tiles can be installed with mortar (for internal or external use) and with a notched trowel.
As these are hand-pressed pieces, it is normal for minimal variations of up to 1 mm in thickness to appear between tiles, so it is advisable for the installer to place them by applying mortar to the subfloor and also to the bottom of the piece, to eliminate the possible differences.
When laying the mortar, it is important to ensure that the mortar has also been applied to the ends of the tile, to prevent them from cracking after the piece is installed.
The hydraulic tile is always laid with a 'dry joint'. In other words, there is practically no space between the pieces, contrary to the norm for other ceramic pieces.
During application, if the mortar spills on the tiles, it is advisable to quickly apply a clean sponge moistened with water, preventing the mass from drying out and penetrating the floor. Otherwise, it is recommended to use 100-gram sandpaper.
Unlike other ceramics, the pieces should never be hit with a rubber hammer, because, in addition to permanently marking the tiles (especially those in light colors), the hammer can break them or generate microcracks that will become evident later. If stains appear, the piece can be sanded lightly.
You should never put cardboard or newspaper directly on the floor, as it can stain the tile. It is advisable that the tiles are covered with plastic.

Custom hydraulic tiles have the same quality and technical specifications as common hydraulic tiles. However, they become an useful option for architects who seek to give a unique touch to a space or enhance certain design operations. This uniqueness is facilitated by the ability of designers to determine color, pattern, geometry, and size.