A springer stone (also called a springing stone) is the first stone of a masonry arch or vault — the stone that sits at the springing point and forms the transition between the straight wall and the curved archwork. The springer stone transfers the forces from the arch down into the supporting wall or pier.
Function of the springer stone
- Starting point of the arch — the springer stone marks the beginning of the curvature
- Load transfer — it channels the angled compressive forces from the arch into the vertical wall
- Shape definition — the angle of the springer stone determines the starting angle of the arch
Springer stones in different arch types
| Arch type | Position of springer stone | Angle |
|---|---|---|
| **Semicircular arch** | On top of the jamb, at the widest point | 0 degrees (horizontal) |
| **Segmental arch** | Slightly above the centre of the opening | Slight inward angle |
| **Pointed arch** | At the widest point | Steep angle |
| **Basket-handle arch** | At the widest point | Varies per segment |
Identifying springer stones in existing masonry
You can recognise a springer stone by:
- The stone sits at the transition from straight to curved masonry
- It is often slightly larger or wider than the other arch stones (voussoirs)
- Sometimes it features a projection or moulding
- In natural stone, it may have a clearly angled cut face
DIY application
When building a decorative brick arch above a window opening:
- Make a centering — determine the arch shape on a wooden centering (formwork)
- Place the springer stones — lay the first arch stones on the centering, tight against the jambs
- Check the joints — the joints taper towards the centre of the arch
- Allow to cure — let the mortar cure for at least 24 hours before removing the centering
Related terms
- Springing point
- Arch
- Keystone
- Vault
- Voussoir