Table 53
POSTS — Supporting Roof and/or Floor Loads
AS 1684.2 — Supplement 6
Sheet & Tile roof
FLA 0 – 20 m²
RLA 5 – 40 m²
Wind N1/N2 – N4
Figure 6.23 — Posts supporting roof and/or floor loads
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AS 1684.2:2021 Figure 6.23 — Post configuration showing floor load area (FLA), roof load area (RLA) and post height between points of lateral restraint.
Inputs
Wind Classification
Wind classification per AS 4055. N1/N2 applies to most sheltered and open terrain. N3 applies to exposed coastal areas. N4 applies to the most exposed non-cyclonic locations.
Timber Grade
Select the stress grade and seasoning. MGP grades are seasoned softwood. Unseasoned timber uses US grades; seasoned uses F or MGP grades.
Roof Type
Sheet roof = any lightweight cladding (Colorbond, zinc, etc.) with total roof+framing+ceiling mass ≤ 40 kg/m². Tile roof = concrete or terracotta tiles with total mass ≤ 90 kg/m².
Floor Load Area (FLA)
Floor load area is the plan area of floor supported by the post. FLA = 0 for posts supporting roof only (no floor load). Use the column equal to or just exceeding your actual FLA.
Roof Load Area (RLA)
Roof load area is the plan area of roof supported by the post. RLA = half the sum of the rafter/truss spans on each side multiplied by the beam spacing.
Please select all inputs to calculate.
Results
AS 1684.2 Supp. 6 — Table 53| Size D×B (mm) | Max. Post Height (mm) |
|---|
Table 53 Notes
- Maximum post heights are based on: sheet roof+framing+ceiling mass ≤ 40 kg/m²; tile roof+framing+ceiling mass ≤ 90 kg/m²; flooring mass ≤ 40 kg/m².
- Post height is the distance between points of lateral restraint (e.g. floor levels providing restraint in two directions).
- Where required to be laminated, posts shall be glue laminated — not nail laminated.
- Wind classification per AS 4055. Cyclonic regions (C1–C4) are not covered.
- NS = Not Suitable.
Find sizes achieving a required post height
Required Post Height (mm)
Wind Classification
Roof Type
Floor Load Area (FLA)
Roof Load Area (RLA)
Please enter required height and select all inputs.
Qualifying Sizes
Disclaimer: For guidance only. Verify results against current AS 1684.2 and applicable project conditions. Not a substitute for professional engineering advice.