3. Special features of clay canal tile roofing

3.1 Conditions of use and maintenance

Use and maintenance requirements are the same as for other clay tile roofs. However, the presence of rainwater drainage channels (running tiles) and the asperities of the roof tiles and coverings make these roofs more demanding in terms of maintenance requirements.

Because of their relatively low slope (30% on average) and high roughness, canal tile roofs are particularly good at trapping plant debris such as pine needles and cones, some of which develop into seeds, mosses and lichens. This debris impedes the drainage of rainwater and compromises the roof's natural ventilation.

Keeping drainage systems in good working order is often simplified by the fact that, in most cases, gutter overhangs make...