Roofing in the United Kingdom

Most houses in the United Kingdom have pitched roofs designed for a mild but wet and windy maritime climate. Local geology has long decided what those roofs are made of: slate in Wales, Cornwall, the Lake District and Scotland, limestone and sandstone "stone slates" in the Cotswolds and Pennines, clay plain tiles and pantiles in the south and east, and thatch across rural England. Since the 20th century, interlocking concrete tiles have become the usual covering on new houses. Because so much of the housing stock is old, conserving traditional roofs is a large part of the UK roofing trade.

Climate and hazards

Wind is the main design load for most UK roofs. Driving rain and gusts at eaves, verges and ridges are why the national code of practice for slating and tiling, BS 5534, was revised in 2014 to require mechanical fixing rather than mortar alone, and to fix perimeter tiles twice. Structural wind and snow loads are calculated using the Eurocodes with UK National Annexes, as referenced in Part A of the Building Regulations. Fire is the special hazard for thatch: between 50 and 80 thatched roofs are lost to fire in the UK each year.

Roofing history

Roman builders brought fired clay roof tiles to Britain after AD 43, and the Roman fort of Segontium at Caernarfon was roofed with local Welsh slate in the late second century. The Cilgwyn quarry in the Nantlle Valley is thought to date from the 12th century, and Delabole in Cornwall has been worked continuously since the 15th century. In medieval towns, fire drove regulation: after a major fire in 1212, London banned new thatched roofs, and the Great Fire of 1666 led to stricter rebuilding rules. Prestige buildings were covered in sheet lead; the roof of Westminster Hall carried about 176 tons of it.

Pantiles were imported from the Netherlands from the early 17th century and became typical of eastern coastal England and Scotland. Scottish slate from the Easdale islands roofed Castle Stalker in 1631, and by 1800 Easdale produced about 5 million slates a year. Industrial quarrying in north Wales began on a large scale at Penrhyn in 1782; by the late 19th century the region produced about a third of the world's roofing slates, and Welsh output peaked at over half a million tons in 1898. Canals and railways spread slate far from the quarries, and corrugated iron, patented in 1829, replaced thatch on many farm buildings.

In the 20th century, concrete roof tiles took over the new-build market. Redland, founded in 1919 as the Redhill Tile Company in Surrey, was one of the early producers. Scottish slate quarrying ended in 1965, and Welsh output fell steeply after the Second World War.

Traditional and vernacular roofs

• Thatch survives on an estimated 60,000 UK properties. The three main English traditions are long straw, combed wheat reed and water reed (often called Norfolk reed). Some roofs in southern England retain base coats more than 500 years old.
• Stone slates (geologically "tilestones") are split from limestone or sandstone and laid in diminishing courses, traditionally hung on oak pegs. Examples include Cotswold, Stonesfield, Collyweston and Horsham stone.
• Natural slate from Wales, Cornwall, Cumbria and Scotland. Welsh slate was sold in named standard sizes; the largest, the Duchess, measures 24 by 12 in (610 by 305 mm).
• Clay plain tiles, small double-lap tiles typical of southern and central England, also hung on walls as tile hanging.
• Pantiles, S-shaped single-lap clay tiles of the east coast, from Norfolk and Yorkshire to Fife.

Roofing today

Concrete interlocking tiles are the most common covering on new houses, with clay tiles and natural or fibre-cement slate also widely used. Most natural slate is now imported, chiefly from Spain, which supplies about 90% of Europe's natural roofing slate; in Scotland, the only genuine Scottish slate available is reclaimed. Flat roofs on extensions, garages and commercial buildings use built-up bitumen, modified bitumen, single-ply membranes and liquid-applied systems, and city planning policies increasingly ask for green roofs. Over 80% of the water reed used for UK thatching is imported.

Codes, standards and regulation

In England, building work must meet the Building Regulations, supported by statutory guidance in Approved Documents. Those most relevant to roofs are Part B (fire, including external fire performance of roof coverings), Part C (resistance to moisture) and Part L (energy, including insulation upgrades when a roof is re-covered). Wales, Scotland and Northern Ireland have their own regulations and guidance. The key product and workmanship standards are BS 5534:2014+A2:2018 for slating and tiling, BS 8612 for dry-fixed ridge, hip and verge systems, and BS 8000-6 for workmanship. Changing the roof material on a listed building normally requires listed building consent; Historic England, Historic Environment Scotland and Cadw publish technical guidance on traditional roofs.

Industry

Major UK pitched-roof manufacturers include BMI Redland (part of BMI Group) and Marley (part of Marshalls). The Austrian group Wienerberger bought the clay tile maker Keymer in 2014 and opened an electrically powered concrete tile plant at Sittingbourne, Kent, in 2025. Penrhyn Quarry in Wales, once the largest slate quarry in the world, is still worked, and Delabole has been worked into the 21st century. Plans to revive Scottish slate quarrying centre on Cullipool on Luing, where minerals planning consent was granted in 2024.

Notable roofs

• Slate Landscape of Northwest Wales, inscribed as a UNESCO World Heritage Site in 2021.
• Westminster Hall, London, whose medieval hammerbeam roof was covered in lead.
• St Paul's Cathedral, whose dome by Christopher Wren is covered in lead over timber.
• Shakespeare's Globe, London, rebuilt in 1997 with a water-reed thatch over a fire-protected roof, after the original theatre burned in 1613 when a stage cannon set its thatch alight.

Local roofing terms

• Delves: shallow surface workings for stone slates.
• Torching: lime mortar applied under slates or tiles to steady them.
• Liggers and spars: hazel rods and pins used to secure thatch.
• Duchess, Countess, Lady: traditional Welsh slate sizes.

Sources and gaps

National statistics on the share of each roof covering in the housing stock: published information is limited.