A saddleback roof (Arabic, jamalun) is a pitched roof that slopes on two sides from a ridgepole to the top of a wall. It has been used since antiquity, especially in rainy areas, to cover buildings with a broad span. In Egypt, saddleback roofs were constructed over basilicas until the Fatimid period, when they were replaced by vaults. A sixth-century example is the Church of the Holy Virgin (Panagia) in the MOUNT SINAI MONASTERY OF SAINT CATHERINE.
The framework of a saddleback roof is a truss, a series of triangular frames formed by a horizontal tie beam resting on two opposite walls and two rafters sloping from the ends of the beam to the ridgepole. A king-post runs from the center of the beam to the ridgepole, and struts attached to the king-post support the rafters. For wide spans, two queen-posts joined by a collar beam replace the king-post. The sloping angle of the rafters facilitates the discharge of rainwater from the surface of the roof, and the rafters prevent any sagging of the tie beams, which are usually very long. For the latter reason, saddleback roofs are found also in areas with low rainfall.
As a rule these tie beams are relatively close together and are rigidly braced by numerous stable horizontal battens to prevent any lateral movement. In Egypt roof trusses were generally made of cedar imported from Lebanon. Native palm was not strong enough and could be used only over a short span where no stress was involved.
The surface of the roof, which could consist of straw, wooden shingles, bricks, or even lead, was fixed over the rafters. Roof tiles of fired clay have so far not been identified in Egypt but appear—at least in the Roman period—to have been not entirely unknown (cf. Steinmeyer-Schareika, 1978, p. 88 and pls. 41, 45, where the structure of roofing plates can be clearly seen on the sloping roof of the small temple). As a rule, the surface of the roof—at least in large buildings—probably consisted of a layer of boards and then a layer of ordinary bricks or limestone slabs, the whole finally being spread with mortar.
Only large buildings had further protection by lead plates, such as many Byzantine churches in Constantinople have and such as Eusebius expressly mentioned for the Church of the Holy Sepulcher in Jerusalem (Eusebuius Vita Constantini 3.36). For the decoration of the inside of the roof, coffering could be applied between the rafters or on a horizontal ceiling. The beams may have been painted, but in most cases they were visible from inside the church even if there was a ceiling. From the tenth century on, the saddleback roof was increasingly replaced by stone vaulting, which was less susceptible to damage from worms and fire (Grossmann, 1982, p. 161, n. 707).
- Butler, Howard Crosby. Early Churches in Syria, pp. 198ff.
- Princeton, 1929; repr., Amsterdam, 1969.
- Choisy, A. L’Art de bâtir chez les romains, 2nd ed., pp. 143ff. Bologna, 1969.
- Forsyth, G. H., and K. Wetzmann. The Monastery of Saint Catherine at Mount Sinai: The Church and Fortress of Justinian. Ann Arbor, Mich., 1973.
- Grossmann, P. Mittelalterliche Langhauskuppelkirchen und verwandte Typen in Oberägypten, p. 161, n. 707. Glückstadt, 1982.
- Lane, E. W. Arabic-English Lexicon. New York, 1955-1956. Steinmeyer-Schareika, A. Das Nilmosaik von Palestrina. Bonn, 1978.