Cotto Tile: History, Craft and Care

Cotto is Zia's Mexican terra cotta tile, pressed by hand from natural clay near San Miguel de Allende. It is left unglazed, so the surface stays matte and true to the clay, and no two tiles share quite the same tone. That character belongs to a long tradition: terra cotta runs through centuries of Mexican architecture, from courtyards to kitchens to covered walkways, and Cotto carries it into rooms of every kind.

The History of Terra Cotta

Terra cotta means "baked earth," and it is one of the oldest building materials still in daily use.

Fired clay appears in the buildings of ancient Mesopotamia thousands of years ago. Greek builders standardized the fired-clay roof tile for durability and fire resistance, and the Romans carried it into villas, baths and aqueducts. Far to the east, builders of the Zhou dynasty were firing roof tiles for China's temples.

In the Americas, the material is bound up with Spanish Colonial architecture, which carried it from Mexico into homes across the American Southwest. The Spanish Colonial Revival of the early twentieth century made red clay tile a defining feature of the style, and that is why terra cotta still reads as instantly "Spanish" today.

Cotto continues that long, global tradition, and widens it.

Hands, Sun and Fire: The Making of Cotto

Cotto is made in three stages. The clay is pressed by hand into molds, dried in open courtyards under the sun for one to two weeks, then high-fired in traditional kilns.

Because each tile is formed by hand and left unglazed, the making stays visible on the surface: tone, shape, edge and thickness shift from piece to piece, and that variation is the tile's character.

There are six colorways. Red Clay, Fired Earth and Adobe are the traditional three; Blanco, Madera and Oscura move the palette away from red and orange. Each is explored in our guide to terra cotta tile colors.

• Red Clay: the deepest red, the raw material at its most natural.
• Fired Earth: a mid-range red, marked by the textured coloring that wood ash leaves in the kiln.
• Adobe: the lightest of the traditional tones, sun-bleached and soft.
• Blanco: a chalky, whitewashed neutral, and the lightest of the collection.
• Madera: a rich brown that brings cocoa to terra cotta's warmth.
• Oscura: a matte black, rare in unglazed clay.

Every colorway comes in far more than the traditional square: rectangles, hexagons and a set of signature shapes, each with a lineage of its own. The eight-pointed Stars & Cross descends from a Moorish pattern that traveled from Andalusian courtyards to colonial Mexico. Oaxaca is a softly curved hourglass whose tiles interlock into a flowing, symmetrical pattern, and the four-tile Durango set builds an abstract geometry of sweeping arcs.

Cotto vs. Cotto Allende

Traditional terra cotta is left unglazed, but Zia also makes Cotto Allende, its glazed counterpart, from the same high-fired clay near San Miguel de Allende.

The difference starts at the surface. Unglazed Cotto is dense and high-fired, with a matte surface of bare clay, finished with a sealer. Cotto Allende carries a hand-applied glaze, and with it a glossier face and a far wider range of color.

That range reaches shades terra cotta isn't known for, like the deep blue of Azul or the pale aqua of Sayulita. Because it is applied by hand, subtle crazing and speckling still show through, so each tile keeps the same handmade variation as Cotto.

That glaze takes Cotto Allende where unglazed terra cotta can't go: into pools and spas. The trade-off runs the other way outdoors. Cotto Allende isn't approved for freeze-thaw climates, while unglazed Cotto is suited to any climate. As with any outdoor project, confirm your choice suits your climate.

The glaze also changes how the tile feels underfoot, so wet floors call for specific grout spacing and slip-resistance treatment. The Cotto Allende installation guide covers those requirements in full.

Bringing Cotto Home: Common Applications

Cotto suits each room for its own reasons: a kitchen floor for its traction, a busy hallway for its density, a courtyard for its ease outdoors. A few spaces in particular have relied on terra cotta for centuries. For a fuller room-by-room look, see our guide to terra cotta floor tile.

Transitional and Outdoor Spaces

Long before "indoor-outdoor living" became a design phrase, terra cotta was doing the work. In Mexican houses it ran from the interior straight out into the courtyard and the covered walkway, so the boundary between inside and out simply dissolved.

Sunrooms, courtyards and patios are designed with that same intention today. Because Cotto is suited to outdoor use in any climate, it can carry the same continuity from a kitchen to a terrace.

Red Clay Cotto in 8x8 or 13x13 squares recreates the classic terra cotta floor of Spanish Colonial and Mexican architecture. The fuller range of colorways and shapes builds on that tradition rather than departing from it.

Cotto's installation guide gives separate guidance for interior and exterior work, including which sealers to use outdoors, where UV light can discolor an interior wax. Make sure your installer follows it in both.

Bathrooms and Showers

Terra cotta has always carried an outdoor sensibility, warm, earthy and sun-touched, which is exactly why designers are bringing it indoors to bathrooms and showers. It turns an everyday shower into a retreat, grounded and natural rather than bright and clinical.

The Adobe 2x6 Rectangle is scaled for smaller spaces and takes to a vertical stack or a herringbone, either of which draws the eye upward and makes a compact shower feel taller.

Cotto has naturally good traction, which suits bathroom and shower floors; a grout joint of at least 1/8 inch adds more. It is sealed before grouting and finished after, and in a bathroom, where the surface sees the most water, that finish is worth getting right.

Commercial and Hospitality Settings

A restaurant patio, a hotel lobby or a shop floor asks a great deal of a material, and Cotto's dense, high-fired clay is made for heavy foot traffic. Its handmade variation lets a busy commercial floor look lived in rather than worn.

The larger formats, the 13x13 square and Big Alcazar, suit the open plans of hospitality spaces. Fewer grout lines and a broader scale let a large room read as one continuous surface rather than a patchwork.

And with so many colorways across Cotto and Cotto Allende, a commercial space doesn't have to commit to a Spanish-style look to have terra cotta's durability. The same drainage and slip-resistance requirements apply in commercial settings as at home, wet-adjacent zones included, and the installation guide covers both.

Notes on Installation

Installing Cotto tile is a job for a professional with real, hands-on experience of terra cotta.

That experience matters most with the special shapes, like Oaxaca and Durango, where non-standard cuts and curving lines make the layout more demanding. Each piece has to meet its neighbors along an irregular edge rather than a straight one, and finding that rhythm takes an installer who has done it before.

Variation is part of a handmade floor's character. For a more uniform look, order more than the standard 15% overage, so the installer has material to choose from and can even out the variation across the floor.

Cotto is always sealed, whether in a dry room or a shower, following Zia's installation instructions. Finish exposed edges with a mitered edge or a Schluter strip. Wear a dust mask and eye protection when working with thin-set, sealants and grout; see Zia's Proposition 65 warnings for full guidance. For project-specific questions, reach the Zia team at info@ziatile.com or 310-844-1170.

Explore Zia's Cotto Collection

Few materials carry so much history into a modern room so easily. Cotto can stay close to the traditional terra cotta floor or push into colors, shapes and settings the tradition never imagined.

Explore the full Cotto collection to find the colorway, shape and size for your space.