Availability and Consumption of Wooden Resource for the Construction of Late Medieval Roof Structures in Finland

Only around two dozen examples of medieval structural timber in Finland's built environment outlasted the past 550 years, all of them as large-scale wooden church roof trusses. This research goes beyond the physical survey of the timber structure and reveals perceptions of the local resource management, more precisely the availability and consumption of wooden building material during the construction of major Late Medieval construction projects in Finland. This research follows the case studies of St. Olaf’s church in Ulvila and St. Henry’s church in Pyhtää. The main methods include field work studies, microscopic wood identification, analysis of pollen diagrams and a review of secondary literature to gain insights into the surrounding medieval built environment and possible forest stands. The findings give an impression of the roof structure’s weight and volume and indicate that Scots pine (Pinus sylvestris) was the preferred building material for the nave roof structure of Pyhtää church, whereas a material shortage of Scots pine (Pinus sylvestris) caused Norway spruce (Picea abies) to be used in the nave roof structure of Ulvila church, most likely caused by a longer and more intense settlement history.