Span tables
Span tables are published supplements to AS 1684 that specify the minimum timber size for each framing member based on span, load, spacing, stress grade, and wind class.
Ask Chalkline about this →Span tables are the published lookup tables that tell a builder or chippy what size timber member to use for a given application in a residential timber frame. They are the practical output of AS 1684 and are published as separate supplement booklets keyed to a specific wind classification, timber stress grade, and species group.
For each framing member type (rafter, floor joist, lintel, bearer, stud, ceiling joist, etc.) the table gives the maximum allowable span for a range of member sizes and spacings. If the required span for the job is shorter than the table allows for the selected size, the member is adequate.
Reading a span table requires four correct inputs: the wind classification for the site, the stress grade and species of the timber, the member spacing (e.g. 450 mm or 600 mm), and the load width (the roof or floor area the member carries). A wrong input in any one of these can produce an undersized member. Using a span table from a superseded edition of AS 1684 (e.g. the 2010 edition) on a new project is a common mistake that can produce non-compliant framing.
Span tables do not cover engineered timber products such as LVL, Glulam, or CLT. Those products use manufacturer-certified span data instead.
Also known as: Framing tables, member size tables.
Category: Structural / Framing.
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Last updated: 2026-05-08. Verified: 2026-05-08.