Medieval Lead Roofs

Lead was the premium metal roofing material of medieval Europe. Cathedrals, abbey churches, royal halls and castle towers were covered in heavy sheets of cast lead laid over timber boarding. Many survive or have been relaid, and lead remains the traditional covering for low-pitched church roofs in Britain and northern Europe.

Roman background

The Romans had already exploited lead widely. It was cheap, as a by-product of silver smelting, and its low melting point made it easy to cast into sheets and pipes. In Rome, when the bronze tiles of the Pantheon were stripped and shipped to Constantinople in 663, Pope Gregory III (731-741) later re-covered the roof with lead sheets.

Medieval use

Lead can be shaped over curves and junctions and joined watertight, which made it suitable for domes, spires and low-pitched church roofs. Medieval craftsmen also gilded, painted or tinned lead on domes, lanterns and spires. Major examples include:

• Westminster Hall, London: the hammerbeam roof built from 1393 carried about 176 tons of lead.
• Notre-Dame de Paris: before the 2019 fire, the roof and spire carried more than 400 tonnes of lead over 13th-century oak.

Loss and recycling

Lead's value made it a target. During the Dissolution of the Monasteries in England in the 1530s and 1540s, monastic roofs were stripped and the lead recast for secular buildings, leaving many abbeys roofless ruins. Theft of church roof lead remains a problem today.

Sheet thickness

Traditional British practice described lead by weight per square foot. The modern Lead Sheet Association codes still follow this: Code 6, for example, weighs about 6 lb per sq ft (roughly 29 kg/m²).

Revival

Decorative leadwork largely moved to country houses after the 1630s, then revived in the late 19th century under Arts and Crafts architects. Sand-cast lead, made by pouring molten metal over a bed of sand, is still produced for conservation work.