What is a beam end?
A beam end is the termination point of a timber beam where it rests in or on a wall, column, or other support. It is the critical location where floor or roof loads are transferred into the load-bearing structure. The beam end is one of the most vulnerable parts of a timber floor and requires careful detailing during design, construction, and maintenance.
Construction and detailing
Traditionally, beam ends are set into pockets (also called beam pockets or joist pockets) formed in the masonry wall. The minimum bearing length is typically 70 to 100 millimetres to ensure safe load transfer. In modern construction, steel joist hangers or beam shoes are widely used as an alternative to building the beam end directly into the wall.
Adequate ventilation around the beam end is essential to prevent moisture accumulation. Historically, beam ends were sometimes coated in tar or bitumen for protection. Current best practice recommends either leaving the beam end untreated to allow the timber to breathe or applying a vapour-permeable preservative.
Risks and common problems
The beam end is the most vulnerable part of a floor joist. Its position within or against the masonry exposes it to several risks:
- Moisture ingress from the surrounding wall, especially at external walls
- Timber decay (wet rot or dry rot) caused by prolonged dampness
- Insect attack from woodworm or longhorn beetle
- Insufficient bearing leading to deflection or slippage of the beam
During renovation of older buildings, inspecting the beam ends is one of the first priorities. Damaged beam ends can be repaired using epoxy resin systems, partial beam replacement, or the installation of steel support brackets.
Related terms
- Beam floor construction
- Beam layer
- Joist hanger
- Wall plate
- Bearing point
- Timber decay
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