Roofing in Italy

Italy has one of the longest continuous histories of tiled roofs anywhere. Clay tiles arrived from Greece in the 7th-6th centuries BC, the Etruscans developed richly decorated terracotta roofs, and Rome turned tile making into an industry whose stamped products still help archaeologists date buildings. The country also holds several of the most important domes ever built.

Climate and hazards

Roofs range from Alpine conditions, with heavy snow, to hot, dry summers in the south and on the islands, where flat roofs and masonry vaults were favoured. Much of Italy is seismic. Heavy roofs and poorly tied timber structures have contributed to earthquake damage, and retrofit practice concentrates on tying roof structures to walls, lightening roofs and strengthening connections. Since 2008 Italy's technical standards have made seismic verification mandatory nationwide. Flooding in regions such as Umbria and Puglia has also been cited as a climate-driven risk to traditional buildings.

Roofing history

Etruscans and Greeks. Fired clay tiles spread from Greece into southern and central Italy within about fifty years of their first use near Corinth around 700-650 BC. Early Villanovan hut urns show houses with sloping roofs, crossed ridge timbers and a smoke hole, and ordinary dwellings were of timber and thatch. Monumental Etruscan temples, from around 600 BC, had timber roofs whose edges were covered in brightly painted terracotta, with antefixes and rows of statues along the ridge; the Apollo of Veii belonged to such a group. Sites such as Poggio Civitate and Acquarossa had tiled roofs and architectural terracottas by the 6th century BC.

Rome. The Romans made pan-and-cover tiling (tegula and imbrex) standard across the empire. From around the mid-1st century BC brick and tile makers stamped their products, at first with a name, later with the owner, the yard supervisor and, from AD 110, the consuls of the year. Production centred on clay-rich estates, such as a brickyard of Domitia Calvilla, mother of Marcus Aurelius, at Bomarzo, and eventually became an imperial monopoly. The Pantheon's concrete dome, completed under Hadrian, is generally described as the largest unreinforced concrete dome in the world.

Byzantine and medieval. San Vitale in Ravenna (547) and St Mark's in Venice show Byzantine domed building, whose domes were covered externally with lead or tiles.

Renaissance and Baroque. Brunelleschi's dome of Florence Cathedral (1420-1436) was built without full centring, and St Peter's dome in Rome, designed by Michelangelo, was completed in 1590.

Traditional and vernacular roofs

• Coppi: curved tiles about 45-50 cm (18-20 in) long and 13-20 cm (5-8 in) wide, needing about 28-30 per m² and weighing about 60-66 kg/m² (12-14 lb/ft²), normally at a pitch of at least 30%. Laid as alternating channels (canali) and covers (coperte), or, mainly in central Italy, over flat embrici in the alla romana or alla fiorentina manner used almost exclusively in Tuscany. Regional variants include the coppo veneto and coppo piemontese.
• Alpine stone roofs: heavy slabs of gneiss or schist (piode, lose) on massive timber structures in the Aosta Valley, Piedmont and Lombardy.
• Trulli: dry-stone houses of Puglia with corbelled stone domes and outer cones of limestone slabs (chianche); the oldest surviving examples date from the mid-14th century.
• Flat roofs and vaults: common in Sicily, Campania and the south, where they also collect rainwater.

Roofing today

Interlocking clay and concrete tiles are widely used on new houses, and S-shaped single-piece tiles that combine channel and cover lay faster than coppi. These are generally not permitted in historic centres, where repairs normally use traditional coppi, often reclaimed.

Codes, standards and regulation

Structural design follows the Norme tecniche per le costruzioni (NTC); the Ministerial Decree of 17 January 2018, in force from 22 March 2018, replaced the 2008 edition. The NTC uses the limit-state method based on the Eurocodes and includes chapters on snow and wind actions and on seismic design, with a strong focus on upgrading existing buildings. Earlier design rules date back to Royal Decree 2229/1939 and Law 1086/1971.

Industry

Italy produces clay coppi both by traditional moulding and by industrial extrusion, with coloured, glazed and artificially aged versions.

Notable roofs

• Pantheon dome, Rome
• Florence Cathedral dome
• St Peter's dome (Vatican City)
• Trulli of Alberobello (UNESCO)
• Byzantine domes of Ravenna and St Mark's, Venice

Local roofing terms

• tetto - roof; copertura - roof covering
• coppo / coppi - curved tile(s); canale - channel tile; coperta - cover tile
• embrice, tegola - flat pan tile
• piode, lose - Alpine stone slabs
• chianche, chiancarelle - limestone slabs of trullo cones
• tetto alla toscana - Tuscan roof of coppi and embrici

Sources and gaps

Census figures on roof materials and information on individual manufacturers: published information is limited.