ornamentally carved eave framing - Italy

The traditional carving minimizes extraneous non-load-bearing weight, and creates drip edges that prevent rot. "[T]he highly evolved technical logic of the traditional roof eave framing detail found in Rome is not readily apparent, and this beautiful detail could easily be mistaken for the purely ornamental. The detail transcends vastly different architectural periods and styles, from antiquity through the Medieval, Renaissance, and Baroque, to late 19th and early 20th-century Neo-Classicism, a strong clue that it is not merely stylistic. Its track record of durability is truly remarkable. Many examples, several hundred years old, constructed of relatively nondurable wood species such as pine, survive outdoors—unpainted, untreated, in a relatively rainy climate. "The triangular form of the projecting beam end is exactly "what it wants to be" structurally. The triangular cut not only eliminates the portion of the beam end that is not needed structurally but also eliminates the portion that would tend to rot (via wicking of moisture through the exposed end) if the beam were simply cut at 90 degrees. The deep overhang of the roof over the beam protects it from moisture under all but the most severe wind-driven rain events. When rain does occasionally wet the beam, a series of beautiful but entirely functional cuts along the diagonal edge of the beam create drip edges to shed water at regular intervals. With such thoughtful, durable design, it is no wonder this detail has survived so well for centuries, despite the vulnerability of pine to rot in the humid, rainy climate of Rome." Bronski, Matthew. "Week 23 - Snow in Rome, and the Choice of Stones for their Durability at Ercolano.In the Footsteps of Vitruvius. February 6, 2010, http://vitruviusfootsteps.wordpress.com/2010/02/16/week-23-%E2%80%93-snow-in-rome-and-the-choice-of-stone-for-durability-at-ercolano/

Photos

  • Photo Credit: Matthew Bronski, PE

    Traditional Eave Framing, Rome, Italy

  • Photo Credit: Matthew Bronski, PE

    Diagrams illustrating the functional reasoning behind the shape of eave framing.

Resources

  1. “Preservation Brief 30: The Preservation and Repair of Historic Clay Tile Roofs.” Accessed October 19, 2015. http://www.nps.gov/tps/how-to-preserve/briefs/30-clay-tile-roofs.htm.