Size and grade

• Introduction
• Span
• Notching
• Support
• Ventilation
• Spacing
• Position
• Size and grade
• Floor loads

Size and grade

The selection of a bearer size and stress grade depends on:

• whether the bearer is under a load bearing wall
• whether the bearer only supports floor loads
• the span of the bearer
• the spacing of the bearer.

AS 1684 'Residential timber framed construction' provides an appropriate span table. The required wind classification for the intended site of the building must also be known. The span tables relate to:

• bearers supporting load bearing walls
  or
• bearers supporting floor loads only.

Both tables provide options for selecting:

• single span bearers
• continuous span bearers
• cantilever bearers.