A cornerstone is the stone at the corner of a building, where two walls meet. In a structural sense it ties the two facade planes together; in a ceremonial sense it is the solemnly laid first stone of a building. The cornerstone therefore has both a structural and a symbolic meaning.
Structural cornerstone
At the corner, the stones of both walls must interlock well, or the corner will split open. To achieve this, the courses are bonded alternately (the corner bond). A heavy natural-stone cornerstone, or a series of blocks (rustication), gives the corner extra strength and a neat appearance.
Ceremonial first stone
The cornerstone or foundation stone is often laid ceremonially at the start of construction. It usually bears an inscription with:
- The date of construction
- The name of the client, architect or a well-known person
- Sometimes a time capsule built in behind the stone
Application
- Monumental buildings — churches, town halls and schools with a commemorative stone
- Corner finishing — rustication or natural stone on the corners of a facade
- Symbolism — the cornerstone as an image for the foundation or core of something
Related terms
- Masonry bond
- Rustication
- Facade stone
- Natural stone
- Springer
- Corner anchor
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