Roof Timber Sizes Australia: Rafters, Joists & Ridge Beams (2026)

A complete reference for the standard structural timber sizes used in Australian roof framing. Covers the most common rafter, ceiling joist and ridge beam dimensions — from 90×45 up to 240×45 — with recommended uses and selection tips by grade and species. This page lists sizes only, not allowable spans: read every span from the published AS 1684 tables.