F17 Hanging Beams Sizing Reference Guide (Australia)
Timber grades, section sizes and questions for professional review. No allowable span values are provided; consult official sources and a qualified designer.
Verify against AS 1684.2
All numeric span values for hanging beams must be confirmed against the official AS 1684.2 (non-cyclonic) or AS 1684.3 (cyclonic) table for your wind classification and load condition. The information on this page is a sizing starting point for builders, owner-builders and homeowners — it is not a substitute for the standard or for engineer sign-off on permitted work.
General roof terminology
The diagram below illustrates a pitched roof, not an application-specific design. It shows where roof members sit in a typical pitched roof, and what "span" and "spacing" mean when you read a sizing table.
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About F17 Hardwood
A grade label alone does not establish suitability. Confirm the actual product, grading evidence and intended use with a qualified designer.
Common species: Spotted Gum, Blackbutt, Sydney Blue Gum, Ironbark.
About hanging beams as a structural member
Hanging beams sit above and at right angles to the ceiling joists, picking up the joists at mid-span so they can reach across a wide room. The ceiling joists hang from the beam (hence the name), which transfers the load out to the walls — letting ceiling joists span much further than they could alone.
Common F17 hanging beam sizes used in Australia
Section sizes most commonly stocked and specified for F17 hanging beams in Australian residential construction. Maximum allowable spans for each section must be confirmed against the AS 1684.2 hanging beam table.
| Section size (mm) | Typical spacing (mm) | Max single span (m) |
|---|---|---|
| 140×45 | 600 | verify against AS 1684.2 Table |
| 190×45 | 600 | verify against AS 1684.2 Table |
| 240×45 | 600 | verify against AS 1684.2 Table |
| 240×63 | 600 | verify against AS 1684.2 Table |
| 240×90 | 600 | verify against AS 1684.2 Table |
- 140×45
- Typical spacing (mm)
- 600
- Max single span (m)
- verify against AS 1684.2 Table
- 190×45
- Typical spacing (mm)
- 600
- Max single span (m)
- verify against AS 1684.2 Table
- 240×45
- Typical spacing (mm)
- 600
- Max single span (m)
- verify against AS 1684.2 Table
- 240×63
- Typical spacing (mm)
- 600
- Max single span (m)
- verify against AS 1684.2 Table
- 240×90
- Typical spacing (mm)
- 600
- Max single span (m)
- verify against AS 1684.2 Table
Sizing guidance and AS 1684 compliance notes
Project-specific sizing guidance is withheld pending qualified review. Ask a qualified designer to assess loads, supports, connections, exposure and the applicable current standard. No size, spacing or span on this reference page is an approved specification.
How to read a F17 hanging beam span table
- Determine your required span — the clear distance between the supports the hanging beam will sit on.
- Note your spacing — typically 600 mm centres.
- Identify your wind classification (N1–N4 non-cyclonic, C1–C4 cyclonic) and load category.
- Look up the AS 1684.2 hanging beam table for F17 and read off the smallest section size whose maximum span exceeds your required span.