It was provided with facings of local soapstone and huge slabs of quartzite slate from the Almlia quarries. Built in the 1770s, the central staircase may orginate from the same time. The central staircase at “ Stiftsgaarden“, the Royal Palace in Trondheim. As we all know, European stone architecture was introduced very late in Norway – together with Christianity around the 11th century – as the Vikings slowly gave up their belief in “paganism”. Thus, contrary to previous knowledge, the quarry may have a history back to the very beginning of stone architecture in Norway. This quarry produced thick slabs of quartzite slate for the streets and staircases of early modern Trondheim, particularly in the late 19th century, but probably also slightly earlier (18th century). On the basis of petrographic studies, Tom Heldal of the Geological Survey of Norway has recently suggested that the slate in question originates at the so-called Almlia quarries, right by the Trondheim Fjord, about 30 km west of Nidarholm. The floor is now covered up, but former archaeological excavations have placed it at about 1100, as confirmed by the excavators Øivind Lunde and Chris McLees, as well as medieval building archaeologist Øystein Ekroll. From the website of Munkholmens venner.Īs described in a previous blog post, the earliest, hard evidence of the use of slate at medieval buildings in Central Norway is the spectacular slate floor at Nidarholm Abbey, situated on a tiny island not far from the city of Trondheim. Nidarholm Abbezr (Munkholmen) near Trondheim: Slate floor from about 1100l.

The slate floor at Nidarholm Abbey in Trondheim

Was the pinning a by-product of the quarrying of roofing slate? Key is the occurrence of slate as pinning stone in joints of fine ashlar masonry. So, what is the evidence? As for roofing, there are only indirect indications since medieval buildings have been hit by numerous fires – there are simply no old roofs left today! But slate and associated stone were clearly used for floors, vaults and other building purposes in the 12th century and especially in the Gothic period from 1200 onwards. However, recent observations in the Trondheim region indicate that slate for roofing – and masonry construction – may have been more widespread, and that the use of slate as a building material for medieval architecture goes back to around 1100. The building was apparently roofed with fine slate from the famous quarries at Jondal in Hardanger, which are still in operation. This document, written by Bishop Arne in 1308, concerns King Haakon’s Hall in Bergen, built from the middle of the 13th century onward. There is, for instance, only one historic reference to slate as roofing material at medieval buildings. It is much more difficult to say anything sensible about the medieval use of slate in the country. Stone that were easy to split could be used for anything from the erection of fine burial chambers to the production of knives – phenomena that have been well documented by numerous archaeological excavations. The use of slate has traditions back to the Neolithic in Norway. It may have a tradition for procurement of slate back to the Middle Ages. The black phyllite schist quarry called “ Sorte Skifer” at Stjørdal in Central Norway.

Old medieval buildings