Zollinger roof

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Residential house with Zollinger roof in Schweicheln-Bermbeck, Hiddenhausen municipality , North Rhine-Westphalia
Interior view of the Augustinus Church in Heilbronn, 1926
Zollinger roof construction Lindenweg Wittenberge

The Zollinger roof is a cantilevered roof structure based on a system construction , in which similar, prefabricated individual elements are assembled in a diamond shape to form a rod network structure. The building system was developed by Friedrich Zollinger , the Merseburg City Planning Officer, at the beginning of the 20th century and is also known as the Zollbauweise or Zoll-Lamellen-Bauweise .

The inch lamellar construction was mainly used for curved roof structures, although it was also intended for other components.

features

The pointed barrel roofs, which were often used in residential construction in the interwar period, are particularly memorable . Compared to the traditional saddle roof with flat roof surfaces, these offer several advantages in residential building:

  • The arched outer shape of the roof and the absence of beams and columns result in better use of space
  • The amount of wood required for the roof structure is reduced by over 40 percent.
  • Because relatively short pieces of wood with small cross-sections are lined up in segments, the need for long straight planks is reduced.
  • Due to the flat load distribution, large spans can be bridged without a support.
  • The assembly of the roof is so easy that building owners or future tenants can help with its construction and thus save costs. However, the setup is more time-consuming.

Usually a Zollinger roof was designed as a pointed pitched gable roof , but occasionally also as a hipped roof (e.g. Evangelical Church in Lauta or Römerhof in Freiburg im Breisgau ). Segment barrel roofs were built especially in hall construction.

It should be noted that an unequivocal assignment as Zollinger roof without a look under the roof skin is not possible, because the plank truss roof by David Gilly or the pointed barrel roof of the Maritime Museum in Kiel also have a formally similar roof shape ; only a look at the exposed roof structure shows the fundamental structural differences.

development

The housing shortage in Germany in the 1920s forced architects and town planners to build apartments as quickly and cheaply as possible. Existing construction techniques have been improved, processes have been streamlined and new ideas have been developed. In Merseburg, city planner Friedrich Zollinger was concerned with developing systems for the factory mass production of standardized structures. He grabbed that from him already proven 1904-1910 inch construction methods , rapid wall construction method using typed formwork and poured concrete, again and developed to fit this one easy to be constructed roof. Compared to the conventional construction method, considerably less wood is used and the space utilization is high. The assembly is so simple that even laypeople can help. However, building the small-scale construction is quite time-consuming.

Based on the design features of the arched plank truss roof ( barrel roof ) with parallel rafters , each of which was glued together by two staggered boards, Zollinger developed the principle of a diamond lamellar roof without planks and rafters. On October 14, 1921, he applied for a patent for his roof construction made of board lamellas. The patent was issued on December 28, 1923. In it are fire separating, plane or curved components committed, allows both the training straight roof surfaces of straight boards than the domed roof, the construction of curved boards.

In addition to saving wood, the arched lamellar construction offered further advantages: Due to the high flexural strength , openings for windows or dormers could easily be cut out of the roof structure. Due to the standardized dimensions of the lamellas, they could be prefabricated in large numbers by machine in the sawmill, regardless of the building. The first roofs were probably built in Merseburg in 1922. The Zollinger lamellar roof was not only used in new residential construction, but due to its special properties also in the construction of public buildings, barns, aircraft and railway halls, stadiums, market halls and churches. From 1921 to 1926 sales were carried out by the Deutsche Zollbau-Licenz-Gesellschaft mbH , which was then replaced by the Europäische Zollbau-Syndikat AG . While the Deutsche Zollbau-Licenz-Gesellschaft marketed the poured concrete process together with the lamella roof as the Zollbau system , the Europäische Zollbau-Syndikat AG only sold the Zollinger roof. The first Zollinger roofs were probably built in Merseburg in 1922.

construction

Off-center knot in customs building

When Zollbau lamella roof similar board or planks pieces are arranged at an angle to each other that in the center of a perpendicular plate, two other diagonally built-up lamellae are incident and by means of lock screw and claw reinforced washer through a long hole are connected to each other. The basic elements, each made up of three lamellar boards that are only rounded on the outside, are twisted against each other, so that a net-like surface structure is created that gives the visual impression of many diamonds arranged side by side and one above the other. The prefabricated slats, which are beveled at both ends, all have the same dimensions 3 × 20 cm² and a length of 2.0 to 2.5 m. With this construction, particularly large spans can be achieved without additional supports.

At the time of the patent application, the statics of the Zollbau lamellar roof could not be calculated exactly. The State Materials Testing Office in Berlin-Lichterfelde therefore carried out practical stress tests on various Zollinger roofs in the summer of 1922 and in the spring of 1923, as did the material testing offices of the technical universities in Dresden and Hanover . Since the results corresponded to the theoretical approximate calculations that Professor Robert Otzen from the TH Hannover had created in the course of the static test, it was ultimately positive. Even if Otzen's subsequent calculations prove to be insufficient from today's perspective, the large number of roofs that have been preserved shows that the Zollinger construction had sufficient bearing reserves.

The flat variant also mentioned in the patent only differed from the curved variant in the use of unrounded instead of rounded lamellas. For the vaulted Zollbau lamellar roof, boards that were curved on both sides were initially used. The degree of curvature on the long sides determined the curvature of the roof. After a short time, you limited yourself to just cutting the upward-facing side of the board in a curved shape; the lower side stayed straight. This meant that the lamellas, which were prefabricated in large quantities, could be used for both roof shapes.

The Zollinger roof can only be proven by approximation . The procedure for this was developed by Robert Otzen . The roof is calculated once as a three-hinged arch and once as a clamped arch. The most unfavorable internal forces are used as a basis for the design. The roof is calculated as a strip from support to support, the cutting forces of the arch are interpolated in the direction of the lamellas. In this way, the respective compression and bending moments can be calculated for the individual slats. Since two ends of the lamellas are connected off-center, additional moments occur in the transverse direction.

Risks

The construction of a Zollinger roof also involved risks. Inadequate care was a factor of uncertainty, as the screw connections had to be checked regularly and tightened if necessary. Inferior wood, incorrect loads and consequential damage to the wood from leaky roof cladding could cause deformations.

There was also the risk that roofs that were too flat could sag over time. Fire experts also complained that the slats, which are only a few centimeters thick, could not withstand a fire for long.

Further development

The Zollingerdach patent already mentions the possibility of using concrete or iron as a material instead of wood. In fact, in 1928 the Junkers company in Dessau developed a forward-looking construction made of thin steel lamellas for buildings with large spans. A bitter, never resolved legal dispute broke out over who was allowed to sell metal lamella technology. The Europäische Zollbau-Syndikat AG and the Junkers company agreed out of court to jointly market the metal construction under the name Junkers-Zollbau-Lamellendach .

Scientists from the University of Technology, Economics and Culture Leipzig (HTWK Leipzig) were honored in 2016 for their research work on the modernization of the Zollinger construction for outstanding achievements in monument preservation in Europe. The research group FLEX under the direction of HTWK Professor Alexander Stahr deals with the question of how the historical Zollinger construction method can be improved with today's knowledge and manufacturing processes and adapted to current requirements and came to the conclusion that many disadvantages of historical construction can be eliminated by digital Planning tools and machine manufacturing can be fixed.

distribution

The first Zollinger lamellar roofs, which are still preserved today, were erected in Merseburg a year before the patent was granted and in the years 1923–1926 they became the standard construction for various building projects. With the help of the Deutsche Zollbau-Licenz-Gesellschaft and subsequently the European Zollbau-Syndikat AG , the Zollinger roof was spread all over the world. Various construction and license brokerage companies were formed at the regional level. In 1926, the Europäische Zollbau-Syndikat AG advertised on a leaflet with 850,000 square meters already built .

Views

  • Residential houses with Zollinger roof in Merseburg

  • Workshop in Höchst in the Odenwald

  • Zollingerdach houses (around 1925) in Coburg

  • Residential houses with Zollinger roof in Magdeburg- Westerhüsen

  • Warehouse in Heilbad Heiligenstadt

  • House in Rodgau, 1926

  • Row house development in Meiningen with a Zollinger roof combination

  • Evangelical Church of the Lautawerk-Nord workers' colony

  • Residential houses with Zollinger roof in Bonn- Friesdorf

  • Hangar on the former airfield Neubiberg near Munich

  • Aircraft hangar Neubiberg: ceiling construction

  • Roof construction of the Zollingerhalle: Organ Center Valley

  • Wittenberge in Lindenweg

  • Bad Malente gymnasium, Ringstrasse district

  • The roof construction of the "Toskana Thermen" in Bad Sulza and Bad Orb are based on the Zollinger and Peselnik principle.

  • Workshop in Herzfelde near Berlin

Locations

Buildings with a Zollinger roof are now in

Web links

Commons : Zollingerdächer  - Collection of pictures, videos and audio files

Individual evidence

  1. ↑ Klaus Winter, Wolfgang Rug: Bautechnik 69 , 1992, issue 4, p. 193
  2. ↑ a b c d e f Florian Zimmermann: Distribution and distribution , in: Das Dach der Zukunft , 1997, pp. 44–53
  3. ↑ Loose concrete poured into formwork and then not or only slightly compacted.
  4. ^ Karl Barth: From the settlement system , Merseburg, 1922, p. 64
  5. ↑ a b Amelie Seck: What is a Zollinger roof? In: German Foundation for Monument Protection (Hrsg.): Monuments . Magazine for monument culture in Germany. No. 4 . Monuments publications, 2019, ISSN  0941-7125 , p. 17 .
  6. ↑ a b How a historical roof structure becomes sustainable . In: htwk-leipzig.de from November 1, 2016. Retrieved on August 7, 2019.
  7. ↑ Klaus Winter, Wolfgang Rug: Bautechnik 69 , 1992, issue 4, pp. 190–197
  8. ^ Charlotte Bairstow: Preservation of monuments in Hessen , 2000, ISSN  0935-8307
  9. ↑ baunetzwissen.de, p. 49113
  10. ^ Robert Otzen: The static calculation of the Zollbau lamellar roofs , in: Der Industriebau , August – September 1923, pp. 96–103
  11. ↑ Charlotte Bairstow: The construction , in: The roof of the future , 1997, p. 20
  12. ↑ Mönck, Willi: Timber construction - basics for dimensioning and construction. 11th edition, Verlag für Bauwesen Berlin Munich
  13. ↑ Charlotte Bairstow, After 1945, Zollinger roofs and related modern wood methods , in: Das Dach der Zukunft , 1997, p. 64
  14. ^ Gold medal for the HTWK architects . In: htwk-leipzig.de from November 16, 2016. Accessed July 15, 2019.
  15. ↑ Karin Heise, Friedrich Reinhardt Balthasar Zollinger - engineer portrait in Deutsche Bauzeitung , 2004, issue 2, p. 72
  16. ^ "Bathing with light and music" - new building of the Toskana Therme Bad Orb , article in the publication "Archive des baths" from January 2011; In: Hess-Timber.com. Retrieved July 24, 2019
  17. ↑ Schleswig-Holstein Archives for Architecture and Civil Engineering, Alfred Schulze holdings, Findbuch Vol. 1.
  18. ↑ The Zollinger roof - less is the future. Galerie Mutter Fourage, 2015, accessed June 30, 2017 .
  19. ↑ Photos of the renovation of the roof with beaver tail covering (Dresden, Salzburger Straße 41) ( Memento from November 29, 2015 in the web archive archive.today )
  20. ↑ International School Römerhof
  21. ↑ Warngauer sawmill in the open-air museum Glentleiten
  22. ↑ FairPack -> Your specialist for removals and furniture storage since 1995. Retrieved November 16, 2019 .
  23. ↑ Autohalle Bramfelder Straße 111 (Hamburg-Barmbek-Nord). Retrieved November 16, 2019 .
  24. ^ Lecture on the family and company history of Heinrich Kappus III. from Idstein ( Memento from May 25, 2019 in the Internet Archive ). In: Wiesbadener Kurier from December 23, 2017
  25. ↑ Elephant House Zoo Leipzig, photo of the roof after the restoration
  26. ↑ Julius Natterer, Thomas Herzog, Michael Volz: Holzbau Atlas Zwei , ed. Institute for International Architecture Documentation, Munich, reviewed reprint 1994, p. 232.
  27. ↑ 130 m industrial hall in Ludwigsburg
  28. ^ Thränhardt / Pfannschmidt: Architecture in Meiningen. Publishing house Resch, Meiningen 2010.
  29. ^ History of the Dürerschule Merseburg
  30. ^ Corner of Koenig-Heinrich-Strasse, across from the Best Western Hotel
  31. ↑ Kreuzkapelle Freiimfelde
  32. ^ Association for District Culture in the Munich Northeast eV (PDF; 9.3 MB). Document from 2010, p. 10. Retrieved on November 24, 2012
  33. ↑ Fraunhofer Information Center for Space and Building IRB ( Memento from August 4, 2012 in the web archive archive.today )
  34. ↑ Memorial Hohemarkstrasse Oberursel . In: ursella.info from July 5, 2018 (PDF; 900 kB). Retrieved July 15, 2019.
  35. ↑ Regensburg old slaughterhouse . In: sanierungspreis.de, Sanierungspreis Holz 2019. Retrieved on July 15, 2019.
  36. ^ Marina Forum Regensburg . In: diereferenz.de of August 31, 2018. Retrieved July 15, 2019.
  37. ^ Exhibition hall Rimini ( Memento from May 28, 2013 in the Internet Archive )
  38. ↑ Special print building with wood , 6/99
  39. ^ Vaihingen - sights, culture, meeting points on stuttgart.de
  40. ↑ Werk, Bauen + Wohnen (Swiss edition), Vol. 92 (2005), p. 41 (or 9 in PDF), PDF download on E-Periodica
  41. ↑ A Zollinger roof does credit to the old hall , article in Teckbote October 7, 2006
  42. ↑ Culture and Organ Center Altes Schloss Valley, accessed on December 13, 2012
  43. ↑ "Infomobil" No. 02/2012, customer magazine of ESWE Verkehrs GmbH, Wiesbaden, p. 10