Topic:
Roof works of churches in the southern district of north - west Mecklenburg

Diplomarbeit

Fachbereich Bauingenieurwesen

Fachhochschule für Technik, Wirtschaft und Gestaltung

Fachbereich Bauingenieurwesen

Inhalt

bearbeitet von:
Jan Brielmann u. Torsten Heier

Aufgabenstellung

Methoden

Ergebnisse

Stand der Erfassung

Home

Datierungsversuch

Vertiefung Stadt- und Gebäudesanierung

Betreuer :
Prof. Dr.-Ing. Frank Braun

Jan Brielmann u. Torsten Heier

Links

Historische Baukonstruktionen,
Baugeschichte, Denkmalpflege

Links

Within the present thesis roof works of 23 churches in the southern district of north-west Mecklenburg were examined. The main focus lay thereby on the schematic recording and documentation of the constructive properties of these roof works. Another task was the judgement of the registered properties with regard to a possible age determination.

A form was used to guarantee a standardized recording of the roof works. This form has been also used for other historical investigations performed by the university of Wismar, however, it was adapted to the special needs of recording the roof works of churches. In this form criteria as roof type, wing units, wood connections, tie signs and wood processing of the churches roof works are registered systematically. Additionally, system sketches and photographs document the recorded properties. Moreover, in co-operation with the department of wood biology of the university of Hamburg dendrochronological examinations were executed in the roof works.  The actual results are presented in the appendix of the work.

Before the evaluation all existing constructive features of the roof works were specified and explained. On the bases of references their usual application intervals could be determined. The evaluation itself took place in sections and based on the established criteria. For a better overview and comparability the properties were represented in tables and diagrams. Because the real interest consisted in the extension of knowledge about sacred buildings of the Middle Ages and the early modern times, the churches Badow, Meetzen, Warin and Zickhusen were recorded, but due to their young age were not taken into account for the evaluation. Consequently 35 roof works of 19 churches were evaluated.

The examined roof works have been established with the exception of the aisles of the basilica in big Salitz as tie beam roofs with roof inclinations between 50 and 65 °.  In 25 cases cross braces were used for additional reinforcement of the bundles. 4 objects contained a chair construction and 9 a hanging work. Some of these constructions were inserted later, so, for example, the hanging works in Cramon and Pokrent. The connections of the rafter pairs in the ridge point are constructed in 21 roof works as halving and in 12 constructions as a tenon. The nodes tie beam / rafter are implemented as straight halvings, hook halvings, swallow tail halvings and mortise dowel joints. In all recorded roof works tie signs were applicated in the cross truss system with side distinction. In 16 cases the counting took place by addition of lines or marks which found application until the 16th century. The counting of 16 other roof works took place in the Roman figure system. As a timber oak was used in 55 percent of the roof works and in 14 percent  conifers were applied. In 31 of the constructions oak as well as conifer was used for construction.

Another result of this investigation is the knowledge that the ceiling constructions were chosen based on the desired space endings than according to other criteria. Also the different ceiling kinds appeared for the whole considered period. Therefore their properties cannot be called on to date the roof trusses.

We concluded that only a very big number of already temporally arranged characteristic features admits the possibility of dating or at least a temporal classification of the roof works. We checked this assumption based on the example of the churches Pokrent and Kirch Grambow. We found out that the roof work of the church in Pokrent and hence also the church itself must have been built earlier than noted in the literature since the existing halving on the ridge and the hook halvings in the rafter / tie beam connection relegate to a time of construction before 1500. The literature dates Pokrent, however, on the end of the 16th century. In Kirch Grambow on the contrary the characteristic features indicate a later time of origin of the roof work than the date given in the literature (around 1300). Here a tie beam roof  without cross trusses, but with a chair and hanging work construction is found. The installation of chair constructions was usually done only since the 15th century. Other indications for a reconstruction of the roof work after the 16th century are the mortise dowel joints of the nodes, the " Roman figure system " of the tie signs and the main use of conifer for the roof structure.

It was intended to verify the results of our evaluation with the dating based on the dendrochronological investigations. As the dating is executed by the department of wood biology of the Hamburg university and the analysis aren’t concluded till this date, the results couldn’t be taken into account within the frame of this work.

The obtained results enable to draw conclusions on the construction history of the churches and the sacred building activity in northwest Mecklenburg. Therefore, our work represents in connection with other works a contribution to the construction history of sacred buildings in Mecklenburg.

Summary