Roofing in Belgium

Belgium is a small, densely built country with a mild, wet and windy North Sea climate. Ceramic roof tiles dominate the lowland north and centre, natural slate is the traditional roof of the Ardennes in the south-east, and reed thatch survives on farmhouses in Flanders and the Kempen. Belgium also played an outsized role in two roofing industries: rolled zinc, through the Vieille-Montagne company near Liège, and fibre cement, through the group that owns the Eternit name.

Climate and hazards

Frequent rain and strong westerly winds make wind uplift and driving rain the main loads on pitched roofs, while in the higher Ardennes snow and frost add to the demands on slate and its fixings. In low-lying Flanders, stormwater from flat roofs is a growing planning concern, as in the neighbouring Netherlands.

Roofing history

The schists and phyllites of the Belgian Ardennes have been worked since prehistory, but Roman and Gallo-Roman slate was used mostly for flooring and tombs rather than roofs. Documentary evidence for roofing slate starts in the Middle Ages: in 1156 the abbey of Saint-Trond (Sint-Truiden) was reportedly roofed with slates from Fumay on the French Meuse; the monks of Orval were confirmed as owners of a slate quarry at Herbeumont in 1269; and slate working at Vielsalm is documented from 1481.

Ardennes slate production grew through the 19th century. In 1840, 480 workers in the province of Luxembourg produced about 17 million slates; by 1876 the province produced about 41 million slates with 1,108 workers, and in 1877 it had 51 open-air and 116 underground workings. Production then declined. Vielsalm's last output came in 1972, and Martelange, the last Belgian slate site, closed at the end of the 1980s.

Belgium was also the cradle of the European rolled-zinc industry. In 1806 the industrialist Jean-Jacques Dony was granted the right to work the zinc deposit at La Vieille Montagne near Liège, and the Société des Mines et Fonderies de Zinc de la Vieille-Montagne, founded in 1837, became a leading producer of building zinc, used on the roofs of 19th-century Paris and elsewhere.

Traditional and vernacular roofs

• Slate (ardoise, Dutch leisteen) on houses, farms and churches of the Ardennes and the Semois valley.
• Ceramic tiles (dakpannen, tuiles) across Flanders, Brabant and Hainaut, including glazed and smoked (blue-grey) finishes.
• Reed thatch (riet) on farmhouses in Flanders and the Kempen.

Roofing today

Ceramic and concrete tiles are the usual coverings on new pitched-roof houses, with natural slate, much of it imported, and fibre-cement slates also common. Flat roofs on terraced housing, apartments and commercial buildings use bituminous, EPDM and other synthetic membranes, and green and blue roofs are promoted in cities for stormwater retention.

Codes, standards and regulation

Building regulation in Belgium is largely a regional matter for Flanders, Wallonia and the Brussels-Capital Region, while European EN standards govern roofing products. Technical guidance for contractors comes from Buildwise, formerly the Belgian Building Research Institute (BBRI), a private research centre founded in 1959 at the initiative of the national federation of building contractors under the 1947 "De Groote" decree-law. Its statutory members are Belgium's more than 120,000 construction companies.

Industry

The Belgian group Etex owns the Eternit trademark for fibre-cement roofing sheets and slates, a material based on the asbestos-cement process patented by Ludwig Hatschek in 1900. The rolled-zinc business of Vieille-Montagne continues today under the VMZinc brand, part of Umicore.

Notable roofs

Belgium's roofing heritage is best seen in its slate country: the former quarries and slate-roofed villages of Herbeumont, Bertrix and Vielsalm in the Ardennes, several of which are now interpreted as industrial heritage sites.

Local roofing terms

• Ardoise / leisteen: slate.
• Dakpan / tuile: roof tile.
• Riet / chaume: thatch.
• Coticule: a fine whetstone from the Vielsalm area, a by-product of the slate belt, used for sharpening razors.

Sources and gaps

National statistics on roof coverings, numbers of thatched roofs and data on Belgium's tile industry: published information is limited.