What a padstone does
A steel beam concentrates a large load on a small area at each end. Brick or block walls can crush under that point load, so a padstone - a strong block under the beam end - spreads the load over a larger area of wall.
Materials
- Precast concrete padstones, the most common choice
- Engineering bricks, laid as a strong bearing course
- Cast in-situ concrete for larger or awkward bearings
- Steel spreader plates, sometimes added between beam and padstone
Size and bearing length
The structural engineer sizes each padstone from the load and the strength of the wall below, and specifies how far the beam must sit on it - the bearing length. Bearings are often in the region of 100-150 mm, but always follow the engineer's design.
Packing and levelling
Beams are packed level on the padstone with steel shims or dry pack mortar, so the load is transferred evenly. Gaps are filled once the beam is in its final position.
Who does what
The builder usually installs the padstones and props the structure. The steel fabricator supplies the beam, with any end plates or spreader plates the engineer specifies, and can install the steel if required.
Learn more about the steel itself in our RSJ vs universal beam guide.