Toothing stones

Toothing stones for an unfinished Baroque upper storey in the farmyard of Thierhaupten Abbey

In masonry, toothing stones are stones or bricks that are left projecting from a masonry wall so that later pieces can be bonded into it. They form a (usually vertical) line of projections intended to interlock with a future wall or extension. If the addition is never built, the exposed stones can provide evidence of uncompleted plans for buildings archaeology.

Construction

Toothing stones can be left in alternate courses, the horizontal layers of a wall. This allows a later continuation along the same line to bond with the existing masonry. The term toothing also describes cutting back part of existing masonry to form a joint with new work.

In historic construction, toothing was also used in external walls built in several leaves, with projections left to bond with an outer facing. Where the intended facing was a decorative façade that was never completed, the projections remained exposed. Examples occur on unfinished brick church façades in Italy, including that of the Church of the Suffragio in Rimini.

Historical terminology

The term tusses occurs in the building contract for Catterick Church in Yorkshire, which required the mason to leave projecting stones for a future vestry. In his 1838 architectural dictionary, John Britton explained the term by reference to the stones' resemblance to teeth or tusks. He recorded tushes as a name still used in parts of England, and toothing as the equivalent London usage.

In German, these projections are called Wartesteine (literally, 'waiting stones'), also Verzahnungssteine or Zahnsteine, and sometimes Wartezahnung. The historical Austrian term was Schmatzen.

Evidence of building history

At Koło Castle in Poland, toothings helped researchers distinguish stages of construction and changes to the planned walls. The residential tower had toothings prepared for perimeter walls. On its eastern side, the later wall matched the intended thickness of 1.8 metres (5.9 ft); on the western side, the wall was 2.10 metres (6.9 ft) thick and overlapped the prepared toothing. Elsewhere in the castle, the joints between walls and toothings helped establish the sequence in which the south-western tower and adjoining curtain walls were built.

Toothing stones have also informed reconstructions. During preparations to rebuild the King's House in Brussels, Pierre-Victor Jamaer found them in the façade. He considered them alongside an early 16th-century report mentioning a tower and gallery. This evidence influenced his decision to add two levels of galleries and a central tower to the reconstructed building, work on which began in 1876.

Toothing left for future construction should be distinguished from similar-looking projections left when an adjoining part of a building has been demolished, particularly in ruins.

Examples

• 
  Regensburg Cathedral: toothing stones for the unfinished Gothic casing around the Eselsturm
• 
  Bibow village church: toothing stones for a west tower planned in the late Middle Ages but never built
• 
  Toothing stones at the Neue Residenz in Bamberg, where the Baroque building scheme was left unfinished
• 
  The unfinished courtyard of the Congress Hall in Nuremberg, with toothing stones
• 
  San Marcuola, Venice: the principal south façade, facing the Grand Canal, left unfinished in the 18th century
• 
  San Petronio, Bologna: toothing stones in the upper part of the unfinished Early Renaissance façade
• 
  Santa Lucia, Bologna: toothing stones in the upper part of the unfinished Baroque façade
• 
  Church of the Suffragio, Rimini: the unfinished façade, with toothing stones
• 
  The church of Saint-Jacques in Compiègne

See also

• Joint (building)

References

Sources

• Adeline, Jules (1891). Adeline's Art Dictionary: Containing a Complete Index of All Terms Used in Art, Architecture, Heraldry, and Archaeology. London: J. S. Virtue and Co., Limited.
• Britton, John (1838). A Dictionary of the Architecture and Archaeology of the Middle Ages. London: Longman, Orme, Brown, Green, and Longmans; the author.
• "Baufugen: Der Zäsur auf der Spur" [Construction joints: Tracing interruptions in building] (in German). Deutsche Stiftung Denkmalschutz. Retrieved 26 September 2026.
• Hennaut, Eric (2018). The Grand-Place. Brussels, City of Art and History. Vol. 56. Translated by Ubiqus Belgium. Brussels: Brussels Urbanism and Heritage. ISBN 978-2-87584-124-7.
• Mothes, Oscar (1884). Illustrirtes Bau-Lexikon [Illustrated dictionary of construction] (in German). Vol. 4: Q bis Z (4th ed.). Leipzig and Berlin: Otto Spamer.
• Piaskowska, Beata; Prarat, Maciej; Różański, Artur; Olszacki, Tomasz; Schaaf, Ulrich (2022). "The ruins of the castle in Koło in the light of the latest architectural and archaeological research, and their conservation issues" (PDF). Architectus (4 (72)): 47–58. doi:10.37190/arc220405.
• "Chiesa del Suffragio" [Church of the Suffragio]. Rimini Turismo (in Italian). 7 May 2024. Retrieved 26 September 2026.
• "Toothing-stones". A Dictionary of Architecture and Landscape Architecture. Oxford University Press. Retrieved 26 September 2026 – via Encyclopedia.com.
• Wanderley, Germano (1878). Handbuch der Bauconstruktionslehre [Handbook of building construction] (in German). Vol. 2: Die Constructionen in Stein (2nd ed.). Leipzig: G. Knapp – via TextGrid Repository.

This article incorporates text from this source, which is in the public domain: Adeline's Art Dictionary (1891), Britton's A Dictionary of the Architecture and Archaeology of the Middle Ages (1838), Mothes's Illustrirtes Bau-Lexikon (1884), and Wanderley's Handbuch der Bauconstruktionslehre (1878), cited above