Steelwork

6.5.5Padstones

Steelwork shall be supported by padstones where required to distribute point loads safely to the supporting structure without undue movement or deflection.

Where a steel beam is supported by masonry, a padstone may be required to spread the load over a larger area to prevent overstressing. Padstones should be in accordance with:

  • the engineer’s design, or
  • the guidance given in this chapter.

Where the inner leaf of the cavity wall contributes to the overall thermal performance of the wall, padstones should:

  • have similar thermal properties to the masonry used for the rest of the inner leaf, or
  • not create a cold bridge.

Table 6: Size of padstones (for steel supporting partition walls)

Notes

1 Padstones are not necessary where the flange dimension of the beam exceeds the length of the padstone given in this table.
2 When steelwork is in line with the wall supporting it, i.e. when acting as a lintel over an opening:
– the flange dimension of the beam should not be more than 50mm greater than the thickness of the supporting wall
– the minimum length of padstone should be 200mm
– the padstone depth should match the coursing of adjacent masonry
– the web of the beam should be over the centre of the wall.
3 The minimum length of steel bearing onto padstone should be 100mm.

Table 7: Size of padstones (for steel supporting floors)

Notes

1 Padstones are not necessary where the flange dimension of the beam exceeds the length of the padstone given in this table.
2 When steelwork is in line with the wall supporting it, i.e. when acting as a lintel over an opening:
– the flange dimension of the beam should not be more than 50mm greater than the thickness of the supporting wall
– the minimum length of padstone should be 200mm
– the padstone depth should match the coursing of adjacent masonry, and
– the web of the beam should be over the centre of the wall.

Padstones should be formed in one unit with a minimum compressive strength of 10 N/mm2 from:

  • in-situ concrete
  • precast concrete
  • concrete blocks
  • clay bricks, or
  • engineering bricks (when less than 215mm x 100mm).