Beam and Post Alignment with Bearings

The rule is straightforward: all steel beams and posts must be seated centrally on their padstones and supporting posts unless the structural drawings specifically note otherwise.

Why Centreline Alignment Matters

Structural calculations assume the beam load is applied directly over the centreline of the support. When a beam is offset to one side of its padstone, an eccentric load is created — the padstone and the masonry beneath it experience both compression and bending, which can exceed the masonry’s capacity.

For heavier beams with substantial end reactions, significant eccentricity at a bearing can cause the masonry or padstone to split, crack, or fail in a progressive manner. This risk is eliminated by keeping the beam central.

What “Centrally on the Padstone” Means

In most domestic wall removals, the beam runs parallel to the wall it replaces. The padstone is positioned centrally under where the beam end will sit — usually centred on the wall thickness (or on the inner leaf of a cavity wall where the beam bears within the inner leaf).

The beam end must sit symmetrically over the padstone, with equal overhang on each side. The structural drawings indicate the padstone position on the element layout; if there is any doubt about where the padstone should be placed, contact the engineer before the padstone is bedded in.

Who Confirms the Final Position?

Final beam positions are confirmed by the architectural consultant and contractor in combination. PorthouseDean provides the structural layout with indicative positions — the architect and builder confirm the exact placement in the context of the as-built wall, cavity and floor arrangement.

In most cases, the beam will be central to the wall or cavity above. The exception is externally where the beam acts as a lintel in a cavity wall with a shelf plate carrying the outer leaf — in that configuration the beam centre may be within the inner leaf rather than the full wall centre.

If There Is Any Doubt, Ask

If the padstone or post position appears unclear from the drawings, do not guess. Contact the engineer before the padstone is bedded. Moving a padstone after concrete has been poured is difficult and expensive; a quick email at the right moment avoids the problem entirely.

Get in touch with PorthouseDean if you need clarification on bearing positions for your project.