Czech roofs are mostly steep, pitched roofs of fired clay. The flat beaver-tail tile (bobrovka) has been one of the most common coverings in the Czech lands for centuries and is still required in many heritage zones, while slate from the Moravian-Silesian uplands roofed many important buildings in Prague and Vienna. Wooden shingles were once common on rural log houses and were gradually replaced by tile, largely because of fire risk.
Climate and hazards
Czechia has a temperate continental climate with cold, snowy winters, especially in the mountain ranges along its borders, and warm summers with thunderstorms. Snow loads, frost and wind-driven rain are the main design concerns; structural design follows the Eurocodes, with snow covered by Eurocode 1, Part 1-3. Fire historically drove the change from shingle and thatch to tile.
Roofing history
The Czech lands have a long carpentry tradition; the historic roof structures of Cheb in western Bohemia are promoted locally as a regional phenomenon and documented in a dedicated project. On log cabins and rural houses, clay beaver-tail tiles gradually replaced flammable wooden shingles, and they became one of the most common roofs in the Czech lands, used on gable, hipped, pyramidal and mono-pitch roofs and on churches.
Roofing slate was quarried in the Moravian-Silesian Region, where deposits around Vítkov and Budišov nad Budišovkou in the Opava district are described as the largest deposits of high-quality splittable slate in Central Europe. Slate mining boomed under the Austro-Hungarian Empire, and slate from the region covered the roofs of major buildings in Vienna and Prague, including the National Theatre. Most mines later closed because of high costs and difficult technology, and slate is now mostly imported, chiefly for restoring historic buildings, although plans to reopen mines were announced in the 2020s.
Traditional and vernacular roofs
- Bobrovka (beaver-tail tile): a flat, rounded-end clay tile, named for its resemblance to the scaly tail of a beaver. The traditional Czech size is about 17.5-18 by 38 cm (6.9-7.1 by 15 in), and each tile weighs about 1.75 kg (3.9 lb). A double-lapped roof weighs about 60 kg/m² (12 lb/ft²), making it one of the heaviest common coverings. Because the tiles have no side grooves or ribs that lock them together, they can follow curves, valleys and dormers. They need a pitch of at least 30°, and double laying needs at least 40°.
- Laying patterns: single laying (loučové), which needs a separate waterproof layer beneath; double "crown" laying (korunové) on battens about 29-33 cm (11-13 in) apart; and double "scale" laying (šupinové) on battens about 14.5-16.5 cm (5.7-6.5 in) apart. A double-laid roof uses about 36 unglazed tiles per square metre.
- Finishes: unglazed (režná) tiles weather to a patina; engobed tiles have a matt clay coating; glazed tiles are the most durable and the most expensive.
- South Bohemian Folk Baroque: in villages such as Holašovice, 18th- and 19th-century farmhouses face the green with richly decorated, multicoloured gables, and smaller buildings such as the forge have simple gable roofs.
Roofing today
Beaver-tail tiles remain common and are often required by the authorities in conservation areas. Concrete versions of the beaver-tail are also made.
Codes, standards and regulation
The main Czech standard for roof design is ČSN 73 1901, Navrhování střech ("Design of roofs"), first published in this form in 1999, with newer parts issued since.
Industry
Czechia has domestic clay and concrete tile production and a historic slate industry in the Moravian-Silesian Region, where Budišov nad Budišovkou has a slate museum.
Notable roofs
- National Theatre, Prague, roofed with Moravian-Silesian slate.
- Holašovice, a UNESCO-listed village of 23 farmsteads around a green, in South Bohemian Folk Baroque style.
- Historic roof trusses of Cheb, studied as a regional phenomenon.
Local roofing terms
- bobrovka - beaver-tail tile
- korunové krytí - double "crown" laying
- šupinové krytí - double "scale" laying
- loučové krytí - single laying
Sources and gaps
Market shares for Czech roofing materials and information on specific manufacturers: published information is limited.
Sources
- Vybíráte si novou střešní krytinu? A co tradiční bobrovky?České stavby · ceskestavby.cz
- Former slate mines set to re-open in Moravia SilesiaRadio Prague International · english.radio.cz
- Černý důl (roofing slate locality)Czech Geological Survey · lokality.geology.cz
- Holašovice Historic VillageUNESCO World Heritage Centre · whc.unesco.org
- ČSN 73 1901 Navrhování střech – Základní ustanoveníTZB-info · tzb-info.cz
- Snow loadWikipedia · en.wikipedia.org
- Historic roof structures – a Cheb phenomenonVisit Cheb · visitcheb.cz