Collonges’s roofs are predominantly made of slate. This technique was probably used back when the town’s buildings were first constructed. North of Brive, there were two slate quarries, in Travassac and Allassac. Slate has great aesthetic qualities since it can be sculpted to fit all sizes. Slates can be scale-shaped, triangular, rectangular or diamond shaped. Alternating these shapes on a roof makes for subtle patterns.
The second type of roofing material traditionally used in Collonges, is sandstone flagstone, particularly upon towers and gables. This type of red stone turns grey when it is time-worn. It can be carved to be straight or curved and scale-shaped. The use of such heavy stone requires for the buildings’ framework to be solid. The stone slates can be pegged to roof planks or placed between lintels. On smaller roofs, much like on towers, the framework is sometimes replaced by stonework, like this cul-de-four vault, where the stone is directly set, forming a tas de charge, which is the French name given to the lower courses of the ribs of a Gothic vault, which are laid in horizontal courses and bonded into the wall, forming a solid mass; which helps bond the ribs, vault and walls together.
In the 19th century, Correzian flagstone and slate were gradually replaced by flat tiles, then interlocking tiles, which were less expensive and easier to install, yet less true to the aesthetics of the town. Thus, ever since the town became a listed site in 1942, interlocking tiles became prohibited, in favour of the progressive reintroduction of slate tiles. Different types of material were used on several roofs under repair. For example, sometimes the gable and lower parts of a roof were tiled with flagstone, while the larger parts were tiled with slate tiles.
Small flat or triangular openings called « outeaux » were added on, to ventilate the buildings’ attics.
Many ceramic or stone finials were placed on rooftops, particularly upon the town’s towers.