What is a Flying Buttress?

A flying buttress is a type of architectural support which is designed to bear the load of a roof or vaulted ceiling, ensuring that the architectural integrity of the structure is preserved. Various forms of the flying buttress were used in architecture as far back as Greek and Roman times, but this unique architectural feature really came into its own in the 12th century, when it flourished under the design trends of Gothic architecture. For a classic example of flying buttresses in action, bring up an image of Notre Dame de Paris, the famous French church, which has some formidable flying buttresses.

A buttress is any sort of architectural support which transfers weight from the walls to a solid pillar. By bearing the bulk of the weight and relieving pressure from the walls, buttresses free up walls for more interesting things, like latticework and windows. Without a buttress, a wall with large windows or ornate latticing could potentially collapse under the strain of a heavy roof and ceiling; as one might imagine, architects invented the buttress at a fairly early stage.

What sets the flying buttress aside from ordinary buttresses is that it literally flies through the air; the buttress is made by building an arch which connects a standard pillar-style buttress with a roof. Originally, these masonry arches were concealed, but in Gothic architecture, they became free-standing, allowing people to clearly see them. In some cases, multiple flying buttresses were actually stacked on top of each other to support an especially heavy structure.

The development of free-standing flying buttresses allowed ceilings to soar in the Middle Ages. The classically huge stained glass windows which many people associate with this period would also not exist without the flying buttress, which is why these architectural features have become so famous. They are also known, incidentally, as arc-boutants.

Depending on the designer, a flying buttress might be left simple, or it might be ornamented with elaborate stonework and sculpture. Some were capped with gargoyles, hideous stone creatures with concealed water spouts which promoted drainage. The construction process for buttresses and the structures they supported was quite complex, as each piece of stone had to be individually cut out, and it was important to cure the masonry slowly, to ensure that it would hold once the structure was completed. Typically, people built flying buttresses on the ground and then raised them into place, a delicate and very dangerous task.