Roofing in Bulgaria

Bulgaria's best-known traditional roofs belong to the houses of the National Revival period, from the end of the 18th century to the end of the 19th, when towns such as Plovdiv, Koprivshtitsa, Melnik and Samokov grew rich on trade. These houses have low-pitched roofs with wide, deep eaves, covered either with clay tiles or, in mountain villages, with heavy slabs of local stone.

Climate and hazards

Bulgaria has hot summers and cold winters, with heavy snow in the Balkan Mountains (Stara Planina) and the Rhodopes. Deep eaves protect walls from sun, rain and snow. Mountain houses are also exposed to fire and to the effects of depopulation and neglect.

Roofing history

The Revival period, which ended with Bulgaria's liberation from Ottoman rule in 1878, produced a distinctive house type, comparable to Ottoman houses in Istanbul, Edirne and Safranbolu. Upper floors were often wider than lower ones, so the roofs of houses on opposite sides of a narrow street can almost touch.

A study of houses in Kotel in the Balkan Mountains describes roofs of three, and sometimes two or four, slopes carried on trusses spanning 10-12 m (33-39 ft), with a ridge rise of 1.5-1.7 m (4.9-5.6 ft) giving a pitch of about 20-25°. Corners were resolved with curved rafters, and the coverings were ceramic tiles bedded in clay, sometimes in a double layer whose weight can make tiles slip. Much of central Kotel burned in 1894; the Kozichkovi houses there, dated by inscriptions to 1880, were restored in 1969 but are now abandoned.

Traditional and vernacular roofs

• Tikli (stone slabs): in the Rhodopes, traditional houses were roofed with flat stones instead of tiles. In the western Rhodope village of Dolen, about 350 traditional houses are covered with tikli, and in Staro Stefanovo in the central Balkan foothills, houses with heavy stone walls also have stone-slab roofs.
• Tiled Revival roofs: clay tiles over timber trusses with large, low eaves, as in Plovdiv, Koprivshtitsa and Kotel.

Roofing today

Many historic mountain houses are threatened by abandonment: when tile roofs fail, rain rots the boards and timber frames, and interventions with concrete and brick can cause new problems. Traditional carpentry skills are declining; one study recorded a master carpenter in his nineties with few commissions or apprentices.

Codes, standards and regulation

As an EU member, Bulgaria applies European product standards and the Eurocodes, including Eurocode 1, Part 1-3 for snow loads.

Notable roofs

• Old Plovdiv and Koprivshtitsa, with Revival houses.
• Dolen, Rhodopes, with stone-slab roofs on about 350 houses, and Staro Stefanovo, an architectural reserve with 95 buildings of monument quality.
• Zheravna, a protected historic village of Revival houses.

Local roofing terms

• tikli (тикли) - stone roofing slabs

Sources and gaps

Details of national regulations for roofs, market data and information on domestic roofing manufacturers: published information is limited.