A ring beam is a continuous reinforced concrete beam on top of the walls of a building that ties all the walls together at the top and distributes the weight of the roof evenly. The ring beam “rings” around the entire building and ensures the walls work together as a single unit.
Why is a ring beam needed?
A roof exerts not only vertical force (weight downward) but also horizontal force: the sloping rafters tend to push the walls outward. This is called spreading force.
The ring beam prevents three problems:
1. Walls being pushed outward — The ring beam holds the walls together and absorbs the horizontal forces from the roof
2. Cracking from uneven loading — If the roof presses harder at certain points, the ring beam distributes the force evenly
3. Wall plate working loose — Without a ring beam, the timber wall plate can shift due to wind loading
When is a ring beam needed?
| Structure | Ring beam needed? |
|---|---|
| Masonry garage with gable roof | Yes — standard |
| Masonry shed | Yes, for larger spans |
| Timber frame shed | No — the top rail serves this function |
| Garden building (lightweight) | No — the weight is too low |
| House | Yes — always |
Build-up
A ring beam is essentially a small concrete beam poured on top of the wall:
| Component | Specification |
|---|---|
| Width | Equal to the wall width (or the inner leaf in a cavity wall) |
| Height | Minimum 15 cm, often 20 cm |
| Reinforcement | Minimum 4 bars dia. 10 mm (2 top, 2 bottom) |
| Stirrups | Dia. 6 mm at 20-25 cm intervals |
| Concrete grade | C20/25 |
In a cavity wall, the ring beam sits only on the inner leaf (the load-bearing wall). The outer leaf is non-structural and does not need a ring beam.
Making a ring beam yourself
1. Formwork — Build formwork on top of the wall. In a cavity wall, the outer leaf can serve as the external formwork.
2. Tie reinforcement — 4 bars dia. 10 mm with stirrups dia. 6 mm at 20 cm intervals. Use spacers for 3 cm cover.
3. Cast-in anchors — Place threaded rods (M12 or M16) in the ring beam where the wall plate will go later. These protrude about 10 cm from the concrete.
4. Pour concrete — Pour all the way around in one go, compact with a vibrating poker.
5. Mount the wall plate — After curing, the timber wall plate is placed on the cast-in anchors and secured with nuts.
Ring beam vs. wall plate
These terms are sometimes confused:
- Ring beam — Concrete beam on top of the wall (structural)
- Wall plate — Timber beam on the ring beam where the rafters rest
The wall plate sits *on* the ring beam, not instead of it.
Related terms
- Wall plate
- Truss
- Reinforcement
- Lintel
- Cavity wall