Coppo (Italian Curved Tile)

The coppo (plural coppi) is the traditional curved clay roof tile of Italy, shaped roughly like a section of a tapering cone. It belongs to the same family as the Spanish teja árabe and the curved tiles of Portugal, and was widely used by the Romans and known to the Greeks and Etruscans before spreading through southern Europe and the Mediterranean.

Size and weight

A typical coppo is 45-50 cm (18-20 in) long and 13-20 cm (5-8 in) wide, though sizes vary by region; recognised regional types include the coppo veneto (Venetian) and coppo piemontese. A roof needs about 28-30 coppi per square metre with overlaps of around 6 cm (2.4 in), and weighs about 60-66 kg/m² (12-14 lb/ft²). The pitch is generally at least 30%.

Laying

Two systems are used:

• Coppi on coppi: alternating rows of tiles laid concave side up as channels (canali) and convex side up as covers (coperte). This is found in both northern and southern Italy and is sometimes called alla diavola.
• Coppi on embrici: curved covers over flat pan tiles (embrici), the direct descendant of the Roman tegula and imbrex. Common mainly in central Italy, where it is called alla romana or alla fiorentina; in Tuscany it was used almost exclusively until modern tiles arrived.

Both systems tolerate generous overlaps, so they adapt well to complex roof shapes. A known weakness is that coppi slowly creep down the slope; versions with anchoring lugs are made to prevent this. In Spain, comparable laying methods range from loose tiles on battens to tiles bedded in mortar on a solid deck.

Manufacture

Coppi were traditionally moulded by hand and are now mostly extruded. Colour depends on the clay or added natural oxides, and glazed and artificially "antiqued" versions are made to match weathered roofs.

Modern alternatives and heritage

Single-piece S-shaped tiles combining channel and cover are faster to lay and resist wind and vibration better, but they are generally not allowed in Italian historic centres. Conservation work therefore keeps coppi in use, often reclaimed from older roofs.