The Role of a Post-Byzantine Timber Roof Structure in the Seismic Behavior of a Masonry Building—The Case of a Unique Type of Timber-Roofed Basilicas in Cyprus (15th–19th Century)

Abstract

In the Troodos area of Cyprus there is a distinctive type of wooden roofed basilicas, dated from the mid-15th to the late-19th century AD, whose unique constructional feature is the existence of two separate but cooperating parts of the roof, the Inner Roof and the Outer Roof. The Inner Roof forms a wooden rigid triangular prism, with horizontal tie-beams and dense inclined rafters, from which the Outer Roof is literary suspended. The two pairs of tie-beams at the western and eastern end of the church are forming, along with the two composite beams on the northern and southern walls, a full timber circumferential binding. This roof type fully adopts the principle of a uniform distribution of loads on multiple paths, and obtains its overall stiffness through numerous partially semi-rigid joints. To achieve this goal, this particular roof structure was developed through years into a unique and cleverly designed bearing system, retaining a high level of simplicity in all construction details. As far as the overall structure is concerned, the timber-roofed churches of Cyprus present a unique system of co-operation between the rigid roof and the stone masonry, achieving in this way the absolutely necessary stiffness for both.