Church Roofs

Abstract

Church Roofs - The roofing of Danish churches in the Middle Ages

In spite of the fact that almost 2000 churches within the modern border of Denmark may be fully or partly dated to the time before the Reformation, very little is known of church roofing in the Middle Ages.

Lead is often thought to have been the dominant form of church roofing from the building of the first stone churches around 1100 AD. Even now, a considerable number of medieval Danish churches have lead roofs (fig. 1). The church accounts of the 17th century hold innumerable notes on repairs to and relaying of older lead roofs. As these roofs are known to last for up to two hundred years, some of them must date to at least the Late Middle Ages, perhaps earlier. This is also seen from the few plumbers' fire­places from the late Middle Ages, which have been preserved in some Danish churches (fig. 2). When it comes to the Early Middle Ages, lead roofed churches are more difficult to confirm. Pits for melting lead have been found in the oldest floor layers of many Romanesque churches. They have traditionally been interpreted as evidence for the making of roof plates, but they may have had other purposes. However, the fact that some Danish church roofs were indeed covered with lead in the Early Middle Ages is witnessed by a correspondence dating to 1188 between the Danish bishop Absalon and a French abbot from the monastery of St. Genevieve in Paris. Here, the Danish bishop's use of lead for roofing purposes is mentioned but nothing is stated about the extent of this use (fig. 42).

In spite of the difficulties in establishing a widespread use of lead roofs in the Early Middle Ages, it cannot be ruled out that this type of roofing played an important part in church building, as lead roofs are usually extremely tight-fitting. Because of this they were perhaps particularly suited for use on the vast roof surfaces of churches, which may have been very vulnerable to stormy weather.

The church of Karise (in the county of Præstø), which was built about 1260, illustrates this. The church gables have the grooves from a lead roof covering a very low-pitched roof. Such a low pitch must have been very vulnerable to snowfall and it is therefore suggested that a lead roofing would have been ideal (fig 3).

These expensive lead roofs, when taken down, would not have been disposed but would have been melted down for reuse or used elsewhere. Therefore, only a limited amount of medieval lead roofing is known. However, in Aastrup church (in the county of Ribe) it has been possible to make a reconstruction of the medieval lead roof on the basis of the marks left by nails in the rafters of a roof dating to about 1300. This roof greatly resembles modern lead roofs (fig. 4,5).

Copper roofs are thought to have been introduced to Denmark around 1500, as is also the case for the Baltic coast of Northern Germany. In Denmark no traces are known of medieval copper roofs but as copper and lead roofs are nowadays constructed using the same principles, this was probably also the case in the Medieval Period. Only a few Danish churches are known to have been covered with a copper roof in the Middle Ages -for instance the cathedrals of Roskilde and Ribe (fig. 6). These two churches are among the best known churches in the country, which may indicate that copper roofs were at this time ascribed considerable prestige.

Board roofing is a well-known feature in Swedish and Norwegian churches, but it seems to have been used to a lesser extent in Denmark (fig. 7). The gables of a few Danish churches do have the impressions of clinker­built roofs. More primitive board roofing, where a single layer of boards is pushed tightly together, has also been documented in this way (fig. 8). All of the known board roofs covered Romanesque church choirs, and in many cases they seem to belong to the time before the nave was erected. This seems to indicate an intermediate function, a theory which is also supported by the church accounts of the 17th century, in which board roofing occurs in connection with the financial crisis brought on by the wars with Sweden. In this period expensive lead roofs were often taken down and replaced with cheaper ones. Shingle roofs and thatched roofs also seem to have played the same role, as cheap replacements for lead roofs.

Shingle roofs are well-known in Norway and Sweden. They are mainly connected with Norwegian stave churches (fig. 9) but in Sweden a few medieval shingles have been found, and a complete shingle roof from the first part of the 12th century has been preserved in the Gotlandic Garde Church (fig. 10, 11, 12). In Denmark, roof shingles are known from Viking Age settlements, such as Trelleborg, dating from c. 980 (fig. 13). This early use has also been deduced from the Viking Age gravestones known as "hogbacks", which are known mainly from Northern England and were supposedly made by Scandinavians. The shape and appearance of these hogbacks is thought to reflect the Viking Age house type with curved walls. In this context it is interesting that their arched roofs sometimes have a shingle pattern (fig. 14). Only a few medieval shingle roofs are known from Danish churches and they have all been connected with Romanesque church building. In Gyrstinge Church (in the county of Sorø) the remains of a built-in covering is visible over the choir –on that resembles the one from Garde.

As opposed to Sweden, no decorated shingles are known from Denmark. On St. Ols Church (in the county of Bornholm) a shingle roof from the time after the Reformation was laid in a pattern of straight­ended and pointed shingles -perhaps the continuation of a much older tradition (fig. 15).

It seems unlikely that shingle roofs would have been used for Danish stave churches to the same extent as in Norway. The reason being that shingles were usually made from pine, which is easily split into thin plates, whereas the prevalent Danish wood type -oak- was less suitable for the purpose. It should also be borne in mind that the Norwegian stave churches are considerably younger than the majority of the Danish ones so direct comparisons probably should not be made. However, from the Renaissance period onwards pine did become the preferred wood type for building construction and shingle roofing in Denmark. As a result, there is plenty of information on shingle roofed churches in Denmark in the 17th century.

Thatched roofs made from reeds and rye straw, which are known from the Viking Age, seem to have been mainly used for secular buildings. As the first Danish stave churches from the 10th and 11th century seem to have taken over the contemporary secular building practice, it is quite possible that they had thatched roofs. One Danish church which did have a thatched roof until 1891 is the half-timbered Oksby Church (Ribe county), which was built between 1450 and 1550 (fig. 32, 33). It seems to be even more difficult to establish thatched roofs on medieval stone churches. However, a rounded-off Romanesque gable-top in Enderslev Church (Præstø county) may be interpreted as allowing for the rounded ridge of a thatched roof, as this form would probably not be very practical in connection with other types of roofing (fig. 31, 34).

A considerable number of different types of clay roof tile are known from Denmark. However, the tiles are often difficult to date as the majority have been found in the ground. These may well give a date for the demolition of the roof but tell nothing of when the roof was made. Several types of roof tile have been produced over a very long period, even into recent times, so precise chronologies for the development of individual types have not yet been made. It is therefore difficult to establish the extent to which the individual tile types were used during the Middle Ages.

Flat roof tiles seem to have played an interesting role in Denmark, as finds from both St. Laurentii church in Roskilde and the Premonstratensian monastery in Lund are thought to date from the first part of the 12th century. As the art of tile making and tile building was supposedly introduced to Denmark around 1150 (fig. 16, 18, 19), this does seem to be a very early date. But as the tiles were reused in brick-built graves from c.1200, a very early use cannot be ruled out. From the Franciscan Monastery in Svendborg there are rectangular roof tiles with nail holes for nailing on to the roof, but these tiles date to the period after the founding of the monastery in 1236. These tiles also have grooves lengthwise, which made it possible to split the tile in half while roofing (fig. 20). Roof tiles with rounded ends -so-called "beavertails"- have also been recognised in connection with medieval church building in Denmark (fig. 21). In spite of the fact that Danish churches were still roofed with flat tiles in the 19th century, archaeological evidence has shown that this particular type was being used for Danish churches from the early days of tile roofing and throughout the Medieval period. However, the extent to which these particular tiles were used cannot be established (fig. 17).

Concave tiles have also been produced in Denmark until recent times, and some churches still have roofs covered with this type of roof tile -as at the church in Sejerø (Holbæk county). It even has a large cross made from yellow tiles on an otherwise red tile roof (fig. 22). Today, concave tiles can also be seen on the stepped gables of a number of churches. Concave tiles are known in a number of variations. The oldest tiles are thought to have been put up without the use of mortar, the tiles being held together with dowels in the upper tile fitting into a cut in the lower one (fig. 23). In time these disappeared and instead the tiles were held in place with mortar. This method of creating a water-tight roof with concave tiles seems to have been the most usual but there was also a system which used underlying, funnel shaped tiles that made a right join with the overlying ones. Alternatively, upper tiles with closed ends which attached to notches in the rows underneath, were used (fig. 24, 25). All the types of clay roof tiles described above have been found in Denmark, as at the monastery at Øm. No precise date for these different methods of roofing has been established nor has a period for the introduction of concave tiles.

The so-called 'Roma tiles' were not common in Northern Europe during the Middle Ages. However, they have been found in two cases: at the monastery at Vissing and in a 14th-century tile oven in Vejle which has been associated with building work on the Dominican monastery there (fig. 26). These two sites are not far from one another and there is reason to believe that the tiles are from the very same kiln. By the middle of the 16th century "winged" tiles were adopted on a large scale in Denmark, although this is a type that had been introduced during the latter part of the 15th century. The early form of this tile is characterised by a large tongue and deep grooves. They are known in a few medieval church buildings, for instance from the monastery at Tvilum (fig. 27, 28).

Special tiles made for covering the ridge of the roof are only known in a few cases in Denmark. From the Franciscan monastery in Svendborg there are a number of well-made angle-shaped tiles with tongues as well as more primitive tiles that were laid by simply overlapping (fig. 29, 30). Both types are known from other sites and may be considered prototypes. No dating exists for these tiles but both are thought to have been made for roofs made of flat tiles, as the ridges of roofs made from concave tiles could just be covered with an upper or lower tile, whereas the ridges of flat tile roofs needed another solution.

It has often been stated that tiles played an important part in medieval church building in Denmark and the large quantity of archaeological material, particularly of concave tiles, seems to confirm this. Nevertheless, it seems reasonable to believe that tiled roofs were mainly associated with medieval brick houses, as kilns woud have been needed to produce the bricks for their construction.

Double-pitched roofs made of quarried stones, where the roofing and roof construction have fused, are known in a few cases from Bornholm and South Eastern Skaane in connection with Romanesque choirs, and then only in connection with high barrel vaulting. In one case, the Øster Marie church on Bornholm, a pointed-arched relief chamber had been built but in some of the other churches of the region the pointed arch occurs in the barrel vault itself (fig. 35, 36, 37). This variation has constructional reasons only and should not be considered an early Gothic element. The models for these churches appear to be Irish, and in Ireland both pure stone roofs and roof constructions identical to the one used for the choir of Øster Marie are known (fig. 38). However, this construction principle is also known in France and the Orkneys and, as Irish influence is extremely unusual in relation to Danish churches, further research is needed to establish such an unusual connection.

In several cases these solid double-pitched roofs on Bornholm seem to be connected to round churches and, as these often contain defensive devices, this particular roofing may be connected to this special function. In the church of Tveje Merløse (Holbæk County), from c. 1150, there is the only Danish example of built-up turreted towers (fig. 39, 40). The twin towers of the western front are crowned by two tufa cupolas, but from where the influence came is not yet clear. Because of the obvious German, mainly Saxon, influence the model for the cupolas has been sought there, but no exact parallels are known in the area. The inspiration has also been sought in the mixed Arab, Byzantine and West European styles which occurred in Sicily after the Norman conquest of the island in the late 11th century. Parallels may also be found in Apulia, which has a special archaic building tradition with many similarities to the cupolas in Tveje Merløse (fig. 41). It is perhaps more likely that the influence actually came from Italy. At the time of the erection of Tveje Merløse church Denmark had good connections with Northern Italy, at least, for the art of brick building was brought to Denmark from that area at this very time. Such a connection can be seen in the early brick churches which show obvious Lombardic influence, as at the monasteries of Sorø and Ringsted.

In addition to the numerous forms of roofing mentioned above, it is possible that slate roofs were used for Danish churches before the Reformation. The first recorded Danish slate roof is from 1497, when Gottorp Castle was given such a roof. However, although the first records of slate roofs are connected with royal buildings, churches may also have had slate roofs. Perhaps we should look for them in Sønderjylland (Southern Jutland) and Slesvig, not far from the large European quarries. Certainly the first slate roofs on houses in the country seem to be concentrated in this part of Denmark.

Thomas Bertelsen