Clay tiles are one of the most distinctive and decorated historic roofing materials.

Traditionally, clay tiles were formed by hand. Legend has it that the Monk and Nun tiles were formed by placing the clay over a worker's thigh.

This manufacturing method naturally results in a tapered barrel-shaped roof tile 6 inches wide at one end, nearly 9 inches at the other, and anywhere from 14 to 19 inches long.

If the myth is true, it would take an army of workers to create enough tiles for a temple's roof. However, in Greece, between 700 and 650 BC, construction labor may have been more plentiful than it is today.

And with taller, shorter, skinny, and less skinny workers, the product specifications would be erratic.

Which is a characteristic that gives the building material its aesthetic charm.

Even if the myth were busted and wooden forms were used from its inception, the tapered characteristic of the "Pan and Cover" roofing tile would still have the numerous benefits for waterproofing and construction techniques it has today.

Speaking of today, you've probably guessed by now that the roof tile we're referring to is more commonly known as the clay Spanish, Mission, or Barrel Tile.

Roof tiles were introduced to North America by European colonizers and typically were traditional designs native to their original country.

Pieces of clay roof tile have been found in archeological excavations of the English settlement at Roanoke Colony dating to 1585 and in later English settlements in Jamestown, VA, and St. Mary's, MD.

Spanish and French colonists brought their designs and styles of roofing tile to areas they settled along what are now the southern United States and Mexico, with Spanish-influenced tile fragments found in St Augustine, FL, and both Spanish and French styles used in New Orleans, LA.

In the 1700s and 1800s, clay roofing tile was popular in colonial American cities due to its fire resistance, especially after establishing urban fire codes.

So, why Monk and Nun?

The name's origins remain uncertain, but we know that in the roofing system, the "Nun" piece is laid with its concave side against the roof, while the "Monk" piece is positioned with its concave side facing upwards.

We know what you're thinking, but its Mission Tile name came from the tile used on the Spanish Missions built throughout Mexico and California.

Shown above Mission San Juan Capistrano.

Why the tapered shape?

Authentic clay barrel roof tiles taper to channel rainwater off the roof by creating a natural slope and an "interlocking" pattern.

The curvature and taper of the tile design directs water toward the lower edge, facilitating efficient drainage.

The overlapping design of the tiles, with the upper tile slightly covering the lower one, further enhances water runoff and provides a weatherproof seal.

Another advantage of its tapered shape, which may be a happy accident (or not), is its ability to easily be installed on rounded roof configurations such as those designed on turrets, bell towers, and rotundas.

Below is a curved wall showing a close-up example of how its shape aids the configuration.

Here's an interesting discovery.

It's not always done, but in some cases, a "Booster" tile is installed as a part of the first row and the rake cap.

As shown below, the Booster Tile gives the first row a slope replicating the profile of the subsequent rows set above.

In some Mission Style homes in California, the starter row might have two boosters thrown in now and then, in addition to an erroneous Booster placed here and there throughout the roof (also shown below).

Clay tile has one of the longest life expectancies among historic roofing materials, 100 years.

The theory is that this practice carried over to emulate our century-old European examples.

Throughout the millennia, rather than replacing a cracked tile, it's suspected that our ancestors slid a new tile in place above as a repair.

Like many architectural features and aesthetic elements in our modern designs, this one probably originates from a practical purpose.

If you're ever in need of details and specifications...

...the drawings above are an example of a document published by MCA Clay Roof Tile in Corona, CA (not a sponsor).

With over a century of experience, MCA has honed the art of turning rich, red clay into stylish clay roofing tiles, providing unique roofing choices and some awesome resource material.

The A-Team discovered the Corona Tapered Mission tile brochure, a downloadable PDF found online, and thought the section references above and the detailed specifications page (not shown) would be helpful tools for building designers who want to specify clay tile roofs.

Therefore, as a convenience, we've placed the 12-page reference material in the Designer Docs Library.

Professional Members will find the resource in a new folder titled "Product Resources."

Check it out at AIBD.org/Designer-Docs, or log into your AIBD account online and link from there.

Have a very happy Thanksgiving,
The A-Team

PS - The A-Team will be out of the office tomorrow and Friday, but the beauty of email is its round-the-clock availability. Should you need assistance, feel free to drop us a message (hey@AIBD.org). While you're thinking about it. We'll get back to you on Monday.