Ground and structure
Buttress
temple boundary wall retaining wall dam warehouse
It is a mass of stone, brick or concrete built against the outside of a wall, propping it so it does not spread or overturn.
What it solves
It receives the lateral thrust of vaults, arches and roofs and carries it down to the ground. In seismic zones it helps a tall earth or masonry wall not to lean outward.
Today
Place it exactly where the load arrives, in line with beams, trusses or arches. Tie it to the wall and to its own foundation so they work together.
Common mistake
Adding a loose buttress, not bonded to the wall and without its own foundation, which separates in the first earthquake.
Tomorrow
The corners of old buttresses often host ferns, mosses and birds. Caring for heritage can coexist with that life if water at the foot of the wall is controlled.
Fact In Gothic cathedrals a lower flying buttress receives the thrust of the vault and a higher one resists the wind that hits the roof.
Where it comes from
- 1French Gothic Paris, France, 1180
The flying buttresses of Notre-Dame de Paris were among the first in a Gothic cathedral. By taking the thrust outside, the walls became thinner and large windows were opened. - 2Earthquake Baroque Paoay, Philippines, 1694 to 1710
The Church of Saint Augustine rests on 24 massive buttresses on its sides and back, a European response adapted to a land of earthquakes. - 3Parish church of Cartago Costa Rica, 1821
After the April 1821 earthquake, the master builders proposed reinforcing its adobe walls with buttresses on the outside, from top to bottom.
Masters
- Mimar Sinan Selimiye Mosque, Edirne, Turkey, 1575
He rests the great dome on eight piers propped by exterior buttresses. He hides them among porticoes and galleries so the interior stays wide and open.
See also
Also in Ground and structure
Diagrams and texts by LDB Arquitectura. They are shared under the CC BY 4.0 license, which allows them to be used and adapted with credit to the source.