Clay tile roofs - Plain tiles

This document completes the and deals specifically with the installation of flat clay tile roofs.

Today's flat tile roofs derive from techniques developed in the 11th and 12th centuries. In many respects, flat tile roofing is similar to slate roofing. In particular, the principle of waterproofing is similar, and is achieved by laying the tiles with staggered vertical joints and overlapping between courses, so that each tile is covered by two others.

One of the consequences of this laying technique is the high number of elements needed to make up 1 m ² of roofing (from 80 to 40 depending on the tile format) and the resulting heavy weight of this type of roofing (around 70 kg/m ² ).

Flat tile roofs are designed for steeply sloping roofs (as opposed to canal and interlocking tiles) and are therefore found in regions where this type of roofing has traditionally been widely used (Burgundy, Franche-Comté, Nivernais, Champagne, Île-de-France, Normandy, Périgord, Poitou and Béarn). This list does not, of course, limit the current use of flat tiles, which are seldom found in regions with predominantly low-slope roofs.

Flat tiles are usually rectangular in shape, but flake or ogival tiles are sometimes used, as is the glazed look specific to the flat tile family.

Today's products frequently include a large number of terracotta accessories designed for the "dry" application of special roofing features, replacing the "masonry" finishes traditionally used. The following text recalls the use of these mortar finishes for certain parts of the structure, but points out the particularities of their behavior and the limitations on use that seem appropriate for this finishing technique.