Bóveda Cañón (Barrel Vault)
To build dramatic high and long barrel vaults, the masons first weld a framework of longer, stronger I-beams onto the corona to act as the side rails of the completed vault. Next, they construct the semi-circular end pieces of the cannon-shaped vault, leaving circular openings for the skylights, which will be added later.
Using the vault's end sections as a pattern, the abañiles design and supervise the building of an iron form just one brick wide. The simple form is designed to slide in the tracks of the I-beams, allowing the workers to lay bricks next to the form in order to accurately gauge the size and curve of the arch.
As the bricks are covered in concrete and put into position, the workers drive small triangular pieces of brick called cuñas into the mortar between the upper edges of the bricks, to put pressure on the arch and add stability to the form.
Barrel vaults are called cañon (cannon) vaults are commonly designed with the bricks set on edge in the cuña design; however, the herringbone designs are a very attractive alternative. Moldings are often added to the sides of the vault to hide lighting fixtures that illuminate the bóveda. When all of the bricks are in place in the vault, the upper surface is finished in the same sequence of layers as described in the low-arch bóveda section.
San Juan Capistrano
The simple church at the Mission of San Juan Capistrano, California, is famed for the swallows that return each March, and we find it interesting because of the way the bóveda de cañón ceiling was built. After the walls were completed, the central area of the early California mission church was filled from floor to ceiling with packed earth. The Franciscans carved the shape of the bóveda in the top of the dirt, and laid their adobe mix and blocks over the arched shape. Once the roof was complete and dry, the dirt was carried back out of the church, leaving the soaring barrel vault.
13th Century blueprint
Even earlier recorded examples of the long vaulted style of bóveda are found on the Balearic Islands just off the coast of Spain. The oldest island church, a tiny rectangle topped with bóveda de cañón, was built in the 13th century, and is a remaining clue to the history of this form of construction. The islands were occupied by the Moors from the 9th century until 1235 when the Catalans from mainland Spain took possession of the islands of Mallorca, Menorca, Ibiza and Formentera. The mix of these two cultures is believed to have inspired bóveda construction.
Brick domes accent many of Lakeside's dramatic rooflines. In the late 1980's and early 1990's, entrepreneur Jaime Hernandez built some of the area's earliest housing developments. Jaime added a brick cupola over the living room or entry of each of his condos and homes, adding interest and light to his home designs and popularizing the architectural detail at Lake Chapala.
You'll see a wide variety of dome designs in Lake Chapala homes.
The domes, which are built "free-hand," without any kind of guide or form, begin with large steel beams welded into a ring that sits on top of the corona. Most cupolas are finished with complex concrete moldings at the lower edge, disguising the indirect lighting that illuminates the dramatic domed interior.
Locally there is a wonderful variety of sizes and heights of domes which feature many of the same brick patterns illustrated above. Domes built with the diminishing circle patterns of the Catalana or cuña, are built by laying the bricks around and around in circles. When the design calls for one of the herringbone patterns, the masons divide the circle into quarters, sixths or eights, and begin building at these points, extending the designs up and together at the top.
This architectural detail is very appropriate here in Mexico where many customs, traditions and designs have been borrowed from the Spanish who were so influenced by 700 years of Moorish domination and influence. Some of the world's oldest grand domes are scattered across Spain, including the Great Mosque of Cordoba, which was started in 784 AD and is topped with a grand ribbed cupola.
Occasionally, the outside surfaces of local domes are decorated with similar ribs and ceramic tile covers the dome. While the tile adds a colorful accent to the architectural design of the house, it does not contribute to the structural value. Other popular cupola design accents include spires, top structures, windows that open for ventilation or skylights that brighten interior spaces.
One of North America's first cupolas was built between 1687 and 1720 near Tucson, Arizona. The center of the grand cupola in the church of the Mission of San Xavier Del Bac rises 55 feet above the floor. This architectural style, which some called Moorish and others classed as Byzantine, is now being termed Spanish Renaissance or Spanish Mission style.
Special thanks go to General Contractor Juan Gilberto Higuera and the maestros of The Little Company in Ajijic who explained procedures to me, answered questions and provided technical information for this article.