Material Marvels: Nidarosdomen

Materials World magazine
,
28 Nov 2018

Nidarosdomen is the world’s northernmost gothic cathedral, centralised in Trondheim, northern Norway. Idha Valeur takes a look at the historical cathedral, Norway’s national shrine.

Building Nidarosdomen commenced in 1070, but was not finished until the year 1300. And over the course of the 700 years since, this beautiful church has hosted many a wedding.

Nidarosdomen, or Nidaros Cathedral, was built on the grave of King Olaf II of Norway, the viking king who christened the country and became the eternal king of Norway. The beloved king, Olav den hellige, died in the Battle of Stiklestad on 29 July 1030. After his death, rumours about miracles involving his corpse began to flourish. One such belief was that a blind man had regained his sight after getting the king’s blood on his hands and rubbing it into his eyes. Also, a year after his death, his grave was dug up and rumour has it that the smell of roses burst out of his casket, and that the king’s hair and nails had grown. Due to these miracles, Bishop Grimkjell declared him holy and he was named Saint Olaf. The king’s remains were then put back into his casket and placed at the altar of the cliff church in Nidaros. A wooden church was built at his original burial place, Nidaros Cape.

The cathedral acts as the central church of the country, and has been used to give blessing to both Harald V of Norway and Queen Sonja of Norway, as well as housing the regalia, which are now exhibited at the Archbishop’s Palace.

A look into soapstone   

Nidarosdomen is predominantly built of soapstone – a metamorphic rock that mainly consists of talc along with varying amounts of micas, chlorite, amphiboles, pyroxenes and carbonates. Soapstone is a soft but dense rock and has high heat resistance, which makes it a good option for architectural use.

Reportedly, it took an estimated 37,000 tonnes of soapstone to build Nidarosdomen.

Dr Per Storemyr, who holds a doctorate on the building blocks of Nidarosdomen, counted 23 types of soapstone, as well as 14 varieties of marble and limestone used in the building of the cathedral, according to researcher at Geological Survey of Norway Tom Heldal’s article Nidarosdomen was built using 70 types of stone published on forskning.no.

Rune Langås, Director of National Centre for Restoration, explained to Materials World that despite Norway having large rock resources, the population have traditionally built most of their houses using wood.

‘With the christening of the country, so came the churches and, according to a papal decree, the churches should be built in stone,’ Langås said. ‘Likewise, the foreign church builders who came to Norway had knowledge of building in stone, not with wood. That the choice fell on soapstone when Nidarosdomen – and other contemporary church buildings and monasteries in the country – should be listed, is seen in the fact that soapstone is a common rock in Norway.

‘The population knew where to find it and knew the material’s use and processing properties. Since very far back in time, soapstone had been used for various purposes in primary industry and households, for example, yarns, spinning wheels, wafers and cookware. It was thus well known that this rock could be relatively easily recovered from the deposits and processed with simple aids.’

Langås explained that the soapstone was mostly locally sourced, which was common for many stone buildings in other countries across the ages. ‘Limestone, sandstone, marble and soapstone are all considered as rocks that are easily extracted and shaped. For building Nidarosdomen, soapstone was the most obvious option,’ he said.

‘Soapstone has high compressive strength, which must be regarded as an advantage in terms of the weight-load the stones further down in the building are exposed to. It is also an advantage that “fresh” and crack-free soapstone absorbs minimal water, compared with other stones. However, this does not mean that it prevents leaks and other moisture-related problems. The problem does not lie with the stone,
but the joints.

‘Something that can be considered an advantage and a disadvantage are the thermal properties of the material. Soapstone stores heat and cold air. The advantage is that heating and cooling takes a long time, which basically contributes to a stable indoor climate. However, condensation-related problems may occur in the case of prolonged heat or cold periods and sudden changes in weather conditions,’ Langås explained.

While it can often seem permanent, soapstone, like all stone, breaks down over time. How long that takes depends on the quality of the material. With the vast restoration project going on at Nidaros Domkirkes Restaureringsarbeider (NDR), a government appointed national centre for the conservation and restoration of historically significant building in stone, the team is continuously on the hunt for good quality soapstone. This work is carried out by the Geological Survey of Norway (NGU), in collaboration with NDR craftsmen

‘As all stone breaks down over time and eventually becomes so bad that it needs to be replaced, so there will always be a need for access to the raw soapstone. Ensuring stable access to stone of the desired quality is a major challenge. Although we have large soapstone deposits in Norway, all quarry activities are closed. The solution may be that NDR, resumes earlier practice and breaks the stone ourselves.

‘Before this can happen, a number of conditions such as material quality need to be clarified, which is done in cooperation with NGU. Quality is not just about durability, processing properties are also important when the material is to be formed accurately and with great detail. In addition, logistics need to be taken into account, as many old soapstone quarries are protected under cultural heritage, so cannot be used again today.’

The restoration work

The cathedral was built in stages over the years and features a nave with aisles, a transept, as well as an octagon facing east. There are two towers at the west front and a mid tower. Several fires hit the cathedral hard during medieval times, and it was left partially ruined from the reformation period up to the 19th Century. Although the five fires caused a vast amount of damage to the cathedral, the octagon is still largely in its original condition – the best part of the cathedral from medieval times, according to the Department of Cultural Heritage of Norway.

And with the fires, so started the restoring work, with the aim to restore the church to its former glory at the end of 1200s. Restoration work started in 1869 and soapstone was collected from the quarries at Bakkaunet og Øysand. ‘Eventually, other clay deposits were used, so that Nidarosdomen, today, consists of stone from at least 60 different quarries around the country,’ Langås said.

NDR was established in 1968 to handle the restoration and maintenance of Nidarosdomen and Erkebispegården (The Archbishop’s yard). The decision to rebuild Nidarosdomen was partly due to it being named in the 1814 Constitution as Norway’s coronation church. ‘In the wake of this followed a growing national awareness that Norway should appear as a significant country with a long and magnificent history. This had to be symbolised and what would be better suited to the purpose than Nidarosdomen in restored medieval splendor?’ Langås said.

NDR consists of six arms called workshops, each with their own specialism. In the stonemason workshop, stone is hewn to make replacement blocks for the ones that cannot be saved and must be replaced. The stonemason workshop also repairs stones with minor damages. The bricklayer workshop’s main responsibility is masonry across the various restoration projects. This workshop also developed the custom-made limestone mortar used in the works today. ‘The mortar is produced at NDR, where we also burn the limestone ourselves,’ Langås said. The blacksmith section produces the tools and aids for other workshops, as well as restoring and maintaining metal items, such as locks, fittings, hinges, fences and even the church steeples.

Building up NDR’s collection of gypsum models is the plaster workshop’s main task. ‘Most of the original collection was stored at the Archbishop’s Palace and was lost in the fire there in 1983. The plaster castings are indispensible 3D documentation of sculptures and ornamentation. These are used as models when the sculptors need to reproduce a broken object in stone. The plasterers also produce stucco rosettes and plaster figures for sale,’ Langås explained.

The carpentry workshop covers restoring, maintaining, refurbishment and fitting work on the buildings within NDR’s administrative area, as well as providing expertise on material quality. And finally, the glass workshop restores the cathedral’s leaded and stained glass windows.

Not only are all individual workshops dedicated to maintaining and restoring this unique cathedral, but they are also part of a national competence centre for the restoration of listed stone buildings. Langås believes the most important aids in the restoration process have been archive material, which has given insight into the choice made by predecessors, the soapstone itself and the lime mortar used.

Celebrating 150 years

Nidarosdomen was declared rebuilt in 2001. In 2019, it will mark 150 years since restoration work began in 1869. Although the cathedral was officially claimed as rebuilt in 2001, by that time NDR was already starting to plan restoration work for the rebuilt cathedral.

‘First we tackled the south façade of the choir, which was completely restored in 2010,’ Langås said. ‘Then restoration of the King entrance was initiated. Due to stability problems, this building part was completely dismantled. We are now in the process of rebuilding it and expect to complete this project in two to three years’ time. Parallel with this we are planning the next restoration project – the north façade of the choir.

‘The plan is to continue this way until we have worked around the entire building. And by the time that is completed, then it is probably time for new restoration of the first restored parts of the cathedral.’

If you happen to be in the northern part of Norway in the winter months, take a walk up to Nidarosdomen and look at the grand cathedral and all of its beautifully restorded details in its finest winter coat.