Keystone
Definition and meaning of Keystone in real estate.
Keystone is the central, wedge-shaped stone at the highest point of an arch that locks all the other stones in position.
In more detail
In traditional masonry, arches are constructed using temporary support frameworks. The arch remains unstable until the keystone is inserted at the very peak, creating a self-supporting structure through compression. Although the keystone does not bear more weight than other stones in the arch, its central position makes it structurally critical.
In modern architecture, keystones are often used decoratively over doors, windows, and entryways to mimic classical design, even if the surrounding wall is supported by steel lintels.
Key facts
| Category | Property Types & Construction |
|---|---|
| Key function | Locks the stones of an arch into a self-supporting structure |
| Applies to | Masonry arches, portals, and decorative window surrounds |
| Also known as | Capstone or crown stone |
An architect designs a stone entryway for a new custom home, incorporating a prominent, decorative keystone at the apex of the arched front door to provide a traditional aesthetic.
Frequently asked questions
Does a modern decorative keystone support weight?
No, in modern homes, a decorative keystone is usually non-structural, while the actual weight above the window or door is supported by a hidden steel lintel.
How does a structural arch work without mortar?
The wedge-shaped stones, including the keystone, are held together by compression, where gravity pushes the stones against each other and channels the weight down to the supporting columns.