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6.3

Part 6.3 Structural steel members

Part 6.3 Structural steel members

(1) Part 6.3, other than clause 6.3.4, applies subject to the limitations set out in H1D6(6).

(2) Part 6.3 need not be complied with if H1D6(5)(a) or (b) are complied with.

(1) Structural steel members may be used as follows:

  1. Bearers supporting a timber floor or non-loadbearing stud wall — in accordance with 6.3.3.
  2. Strutting beams supporting roof and ceiling loads — in accordance with 6.3.4.
  3. Lintels supporting roof, ceiling, frame and timber floor — in accordance with 6.3.5.
  4. Columns — in accordance with 6.3.6.

(2) Structural steel members in (1)(a), (b) and (c) must have a minimum nominal yield strength of 250 MPa.

(3) The yield strength of structural steel members in (1)(d) is nominated in 6.3.6.

(4) Structural steel members described in this Part must be protected against corrosion in accordance with 6.3.9.

Structural steel bearers must comply with the following:

  1. Effective bearer spacing must be determined in accordance with—
    1. for single span joists — Table H1D6a and Figure H1D6d; and
    2. for continuous span joists — Table H1D6b and Figure H1D6e.
  2. Maximum acceptable bearer spans must be determined in accordance with—
    1. for single spans — Tables 6.3.3a and 6.3.3c; and
    2. for continuous spans — Tables 6.3.3b and 6.3.3d.
  3. All loads along the bearer must be evenly distributed.
  4. The difference in distance between supports for continuous span bearers must not be more than 10% of the span.
  5. Fixing of joists and columns to structural steel bearers must comply with 6.3.7.
  6. Bearers must be supported by structural steel columns that comply with 6.3.6 and are fixed in accordance with 6.3.7.
Table 6.3.3a Maximum bearer span (m) — single span — bearer supporting timber floor and 3 m high non-loadbearing internal wall
Steel section Effective load width (m)
1.8 2.4 3.0 3.6 4.2
125 TFB 4.2 4.0 3.9 3.8 3.6
180 UB 16.1 5.6 5.4 5.3 5.1 4.7
200 UB 18.2 6.4 6.2 6.0 5.8 5.4
250 UB 25.7 8.3 8.0 7.8 7.6 7.1
250 x 150 x 9 RHS 9.3 9.0 8.8 8.6 8.4
250 x 150 x 5 RHS 8.0 7.8 7.6 7.1 6.6
310 UB 32.0 10.0 9.7 9.4 9.2 8.6
125 x 75 x 2 RHS 2.9 2.6 2.3 2.2 2.0
125 x 75 x 3 RHS 3.5 3.3 3.2 2.9 2.7
150 x 50 x 2 RHS 3.3 2.9 2.6 2.4 2.3
150 x 50 x 3 RHS 3.7 3.6 3.4 3.1 2.9
100 TFB 2.9 2,8 2.7 2.5 2.4
150 PFC 5.2 5.0 4.9 4.7 4.6
180 PFC 6.1 5.9 5.8 5.6 5.4
200 PFC 6.8 6.6 6.4 6.2 5.9
250 PFC 8.9 8.6 8.4 8.2 8.0
300 PFC 10.4 10.1 9.8 9.5 9.3
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 0.92 kN/m permanent wall, permanent member self-weight, 1.5 kPa or 1.1 kN imposed.
  2. Load combinations included are 1.35G and 1.25G+1.5Q for ULS and G + 0.7Q for SLS with a maximum deflection of span/300.
  3. Bearers are assumed to have intermediate lateral restraints at joist locations and are considered fully laterally restrained.
Table 6.3.3b Maximum bearer span (m) — continuous span — bearer supporting timber floor and 3 m high non-loadbearing internal wall
Steel section Effective load width (m)
1.8 2.4 3.0 3.6 4.2
125 TFB 5.2 4.6 4.2 3.9 3.6
180 UB 16.1 6.8 6.0 5.5 5.1 4.7
200 UB 18.2 7.7 6.9 6.2 5.8 5.4
250 UB 25.7 10.2 9.1 8.3 7.6 7.1
250 x 150 x 9 RHS 12.4 11.5 10.5 9.8 9.1
250 x 150 x 5 RHS 9.5 8.4 7.7 7.1 6.6
310 UB 32.0 12.3 11.0 10.0 9.2 8.6
125 x 75 x 2 RHS 2.9 2.6 2.3 2.2 2.0
125 x 75 x 3 RHS 4.0 3.5 3.2 2.9 2.7
150 x 50 x 2 RHS 3.3 2.9 2.6 2.4 2.3
150 x 50 x 3 RHS 4.2 3.7 3.4 3.1 2.9
100 TFB 3.4 3.0 2.7 2.5 2.4
150 PFC 6.5 5.8 5.3 4.9 4.6
180 PFC 7.8 6.9 6.3 5.8 5.4
200 PFC 8.5 7.6 6.9 6.4 5.9
250 PFC 11.6 10.4 9.5 8.7 8.2
300 PFC 13.4 12.0 10.9 10.1 9.4
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 0.92 kN/m permanent wall, permanent member self-weight, 1.5 kPa or 1.1 kN imposed.
  2. Load combinations included are 1.35G and 1.25G+1.5Q for ULS and G + 0.7Q for SLS with a maximum deflection of span/300.
  3. Bearers are assumed to have intermediate lateral restraints at joist locations and are considered fully laterally restrained.
Table 6.3.3c Maximum bearer span (m) — single span — bearer supporting tiled floor and 3 m high non-loadbearing internal wall
Steel section Effective load width (m)
1.8 2.4 3.0 3.6 4.2
125 TFB 3.9 3.7 3.5 3.4 3.3
180 UB 16.1 5.2 5.0 4.8 4.6 4.4
200 UB 18.2 5.9 5.6 5.4 5.2 5.0
250 UB 25.7 7.7 7.3 7.1 6.8 6.6
250 x 150 x 9 RHS 8.7 8.3 8.0 7.7 7.5
250 x 150 x 5 RHS 7.5 7.1 6.9 6.6 6.1
310 UB 32.0 9.3 8.9 8.5 8.2 8.0
125 x 75 x 2 RHS 2.7 2.4 2.2 2.0 1.9
125 x 75 x 3 RHS 3.2 3.0 2.9 2.7 2.5
150 x 50 x 2 RHS 3.0 2.7 2.4 2.2 2.1
150 x 50 x 3 RHS 3.4 3.3 3.1 2.9 2.7
100 TFB 2.7 2.6 2.5 2.3 2.2
150 PFC 4.8 4.6 4.4 4.2 4.1
180 PFC 5.7 5.4 5.2 5.0 4.9
200 PFC 6.3 6.0 5.8 5.6 5.4
250 PFC 8.3 7.9 7.6 7.3 7.1
300 PFC 9.7 9.2 8.9 8.6 8.3
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 0.92 kN/m permanent wall, permanent member self-weight, 1.5 kPa or 1.1 kN imposed.
  2. Load combinations included are 1.35G and 1.25G+1.5Q for ULS and G + 0.7Q for SLS with a maximum deflection of span/300.
  3. Bearers are assumed to have intermediate lateral restraints at joist locations and are considered fully laterally restrained.
Table 6.3.3d Maximum bearer span (m) — continuous span — bearer supporting tiled floor and 3 m high non-loadbearing internal wall
Steel section Effective load width (m)
1.8 2.4 3.0 3.6 4.2
125 TFB 4.8 4.3 3.9 3.6 3.3
180 UB 16.1 6.3 5.6 5.1 4.7 4.4
200 UB 18.2 7.2 6.4 5.8 5.3 5.0
250 UB 25.7 9.5 8.5 7.7 7.1 6.6
250 x 150 x 9 RHS 11.6 10.8 9.8 9.1 8.5
250 x 150 x 5 RHS 8.8 7.8 7.1 6.6 6.1
310 UB 32.0 11.5 10.2 9.3 8.5 8.0
125 x 75 x 2 RHS 2.7 2.4 2.2 2.0 1.9
125 x 75 x 3 RHS 3.7 3.3 3.0 2.7 2.5
150 x 50 x 2 RHS 3.1 2.7 2.4 2.2 2.1
150 x 50 x 3 RHS 3.9 3.4 3.1 2.9 2.7
100 TFB 3.2 2.8 2.5 2.3 2.2
150 PFC 6.1 5.4 4.9 4.5 4.2
180 PFC 7.2 6.4 5.8 5.4 5.0
200 PFC 8.0 7.1 6.4 5.9 5.5
250 PFC 10.9 9.7 8.8 8.1 7.6
300 PFC 12.5 11.2 10.1 9.4 8.7
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 0.92 kN/m permanent wall, permanent member self-weight, 1.5 kPa or 1.1 kN imposed.
  2. Load combinations included are 1.35G and 1.25G+1.5Q for ULS and G + 0.7Q for SLS with a maximum deflection of span/300.
  3. Bearers are assumed to have intermediate lateral restraints at joist locations and are considered fully laterally restrained.

Structural steel strutting beams must comply with the following:

  1. Acceptable strutting beam spacing must be determined in accordance with—
    1. for single span rafters — Table H1D6a and Figure H1D6a; and
    2. for continuous span rafters — Table H1D6b and Figure H1D6b.
  2. Maximum acceptable strutting beam spans must be determined in accordance with—
    1. for metal sheet roofs — Tables 6.3.4a, 6.3.4b, 6.3.4c, 6.3.4d, 6.3.4e or 6.3.4f; and
    2. for tiled roofs — Tables 6.3.4g, 6.3.4h, 6.3.4i, 6.3.4j, 6.3.4k or 6.3.4l.
  3. Any point load applied must be located within the middle third of the strutting beam.
  4. Strutting beams must be tied down in accordance with H1D6(3) where supporting metal roofs.
  5. Fixing and any cutting of strutting beams must comply with 6.3.7.
  6. Strutting beams must be supported by structural steel columns that comply with 6.3.6 and be fixed in accordance with 6.3.7.
Table 6.3.4a Maximum combined strutting/hanging beam span — combined strutting/hanging beam supporting metal sheet roof and plasterboard ceiling — roof load area = 4 m2
Section Ceiling load width (m)
1.8 3.6 6.0
125 TFB 3.5 3.3 3.2
150 UB 14.0 3.6 3.4 3.3
200 UB 18.2 4.5 4.3 4.1
250 UB 31.4 6.8 6.5 6.2
310 UB 46.2 8.9 8.5 8.1
100 TFB 2.0 2.0 1.9
150 PFC 4.7 4.5 4.3
200 PFC 5.5 5.3 5.0
250 PFC 7.5 7.1 6.8
300 PFC 7.8 7.5 7.1
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
Table 6.3.4b Maximum combined strutting/hanging beam span — combined strutting/hanging beam supporting metal sheet roof and plasterboard ceiling — roof load area = 8 m2
Section Ceiling load width (m)
1.8 3.6 6.0
125 TFB 2.6 2.6 2.5
150 UB 14.0 2.8 2.7 2.7
200 UB 18.2 3.6 3.5 3.4
250 UB 31.4 5.5 5.4 5.2
310 UB 46.2 7.3 7.1 6.9
100 TFB 1.4 1.4 1.4
150 PFC 3.7 3.6 3.5
200 PFC 4.4 4.3 4.1
250 PFC 6.0 5.8 5.7
300 PFC 6.3 6.2 6.0
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
Table 6.3.4c Maximum combined strutting/hanging beam span — combined strutting/hanging beam supporting metal sheet roof and plasterboard ceiling — roof load area = 12 m2
Section Ceiling load width (m)
1.8 3.6 6.0
125 TFB 2.2 2.2 2.2
150 UB 14.0 2.4 2.3 2.3
200 UB 18.2 3.1 3.0 3.0
250 UB 31.4 4.8 4.7 4.6
310 UB 46.2 6.4 6.3 6.1
100 TFC 1.1 1.1 1.1
150 PFC 3.1 3.1 3.0
200 PFC 3.7 3.7 3.6
250 PFC 5.2 5.1 5.0
300 PFC 5.5 5.4 5.3
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
Table 6.3.4d Maximum counter-strutting beam span — counter-strutting beam supporting metal sheet roof and plasterboard ceiling — roof load area = 4 m2
Section Ceiling load area (m2)
0 6 12
125 TFB 3.9 3.5 3.2
150 UB 14.0 4.0 3.7 3.4
200 UB 18.2 5.4 4.9 4.6
250 UB 31.4 8.9 8.2 7.7
310 UB 46.2 12.0 11.3 10.7
100 TFB 2.0 1.8 1.6
150 PFC 5.9 5.3 4.9
200 PFC 7.1 6.5 6.0
250 PFC 10.1 9.3 8.7
300 PFC 10.5 9.8 9.2
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G and 1.25G + 1.5Q, 1.25G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G+WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A ceiling load area of “0” must be used for strutting beams not supporting ceiling loads.
Table 6.3.4e Maximum counter-strutting beam span — counter-strutting beam supporting metal sheet roof and plasterboard ceiling — roof load area = 8 m2
Section Ceiling load area (m2)
0 6 12
125 TFB 2.7 2.6 2.4
150 UB 14.0 2.9 2.8 2.6
200 UB 18.2 4.0 3.8 3.6
250 UB 31.4 6.8 6.5 6.2
310 UB 46.2 9.6 9.2 8.8
100 TFB 1.4 1.3 1.2
150 PFC 4.2 4.0 3.8
200 PFC 5.2 4.9 4.7
250 PFC 7.7 7.3 7.0
300 PFC 8.2 7.8 7.5
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G and 1.25G + 1.5Q, 1.25G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G+WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A ceiling load area of “0” must be used for strutting beams not supporting ceiling loads.
Table 6.3.4f Maximum counter-strutting beam span — counter-strutting beam supporting metal sheet roof and plasterboard ceiling — roof load area = 12 m2
Section Ceiling load area (m2)
0 6 12
125 TFB 2.2 2.1 2.0
150 UB 14.0 2.4 2.3 2.2
200 UB 18.2 3.3 3.2 3.0
250 UB 31.4 5.7 5.5 5.3
310 UB 46.2 8.2 7.9 7.7
100 TFB 1.1 1.0 1.0
150 PFC 3.4 3.2 3.1
200 PFC 4.2 4.1 3.9
250 PFC 6.4 6.2 6.0
300 PFC 6.9 6.6 6.4
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G and 1.25G + 1.5Q, 1.25G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G+WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A ceiling load area of “0” must be used for strutting beams not supporting ceiling loads.
Table 6.3.4g Maximum combined strutting/hanging beam span — combined strutting/hanging beam supporting tiled roof and plasterboard ceiling — roof load area = 4 m2
Section Ceiling load width (m)
1.8 3.6 6.0
125 TFB 2.7 2.6 2.6
150 UB 14.0 2.8 2.8 2.7
200 UB 18.2 3.6 3.5 3.4
250 UB 31.4 5.5 5.4 5.2
310 UB 46.2 7.2 7.1 6.9
100 TFB 1.6 1.5 1.5
150 PFC 3.7 3.7 3.6
200 PFC 4.4 4.3 4.2
250 PFC 6.0 5.8 5.7
300 PFC 6.3 6.1 6.0
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.84 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
Table 6.3.4h Maximum combined strutting/hanging beam span — combined strutting/hanging beam supporting tiled roof and plasterboard ceiling — roof load area = 8 m2
Section Ceiling load width (m)
1.8 3.6 6.0
125 TFB 2.0 2.0 2.0
150 UB 14.0 2.2 2.1 2.1
200 UB 18.2 2.8 2.8 2.7
250 UB 31.4 4.4 4.3 4.3
310 UB 46.2 5.8 5.7 5.6
100 TFB 1.1 1.1 1.1
150 PFC 2.8 2.8 2.8
200 PFC 3.4 3.3 3.3
250 PFC 4.7 4.6 4.6
300 PFC 5.0 4.9 4.8
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.84 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
Table 6.3.4i Maximum combined strutting/hanging beam span — combined strutting/hanging beam supporting tiled roof and plasterboard ceiling — roof load area = 12 m2
Section Ceiling load width (m)
1.8 3.6 6.0
125 TFB 1.7 1.7 1.7
150 UB 14.0 1.8 1.8 1.8
200 UB 18.2 2.4 2.4 2.4
250 UB 31.4 3.8 3.8 3.7
310 UB 46.2 5.0 5.0 4.9
100 TFB 0.9 0.9 0.9
150 PFC 2.4 2.4 2.3
200 PFC 2.9 2.8 2.8
250 PFC 4.0 4.0 3.9
300 PFC 4.3 4.2 4.2
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.84 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
Table 6.3.4j Maximum counter-strutting beam span — counter-strutting beam supporting tiled roof and plasterboard ceiling — roof load area = 4 m2
Section Ceiling load area (m2)
0 6 12
125 TFB 3.4 3.1 2.9
150 UB 14.0 3.5 3.3 3.0
200 UB 18.2 4.7 4.4 4.1
250 UB 31.4 7.9 7.4 7.0
310 UB 46.2 10.9 10.4 9.9
100 TFB 1.7 1.6 1.4
150 PFC 5.1 4.6 3.6
200 PFC 6.2 5.7 5.4
250 PFC 9.0 8.4 8.0
300 PFC 9.5 8.9 8.5
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A ceiling load area of “0” must be used for strutting beams not supporting ceiling loads.
Table 6.3.4k Maximum counter-strutting beam span — counter-strutting beam supporting tiled roof and plasterboard ceiling — roof load area = 8 m2
Section Ceiling load area (m2)
0 6 12
125 TFB 2.3 2.2 2.1
150 UB 14.0 2.5 2.4 2.3
200 UB 18.2 3.4 3.3 3.2
250 UB 31.4 5.9 5.7 5.5
310 UB 46.2 8.5 8.2 7.9
100 TFB 1.2 1.1 1.0
150 PFC 3.6 3.4 3.3
200 PFC 4.4 4.2 4.1
250 PFC 6.7 6.4 6.2
300 PFC 7.2 6.9 6.7
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A ceiling load area of “0” must be used for strutting beams not supporting ceiling loads.
Table 6.3.4l Maximum counter-strutting beam span — counter-strutting beam supporting tiled roof and plasterboard ceiling — roof load area = 12 m2
Section Ceiling load area (m2)
0 6 12
125 TFB 1.8 1.8 1.7
150 UB 14.0 2.0 1.9 1.9
200 UB 18.2 2.8 2.7 2.7
250 UB 31.4 5.0 4.8 4.7
310 UB 46.2 7.1 7.0 6.8
100 TFB 0.9 0.9 0.8
150 PFC 2.8 2.7 2.7
200 PFC 3.6 3.5 3.4
250 PFC 5.5 5.4 5.2
300 PFC 5.9 5.8 5.6
Table Notes
  1. Load accounted for includes 0.2 kPa permanent ceiling, 0.4 kPa permanent roof, permanent member self-weight, 0.25 kPa imposed roof, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Strutting beams are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A ceiling load area of “0” must be used for strutting beams not supporting ceiling loads.

Structural steel lintels must comply with the following:

  1. Spans for lintels supporting roofs, frames and timber floors must be determined in accordance with—
    1. for metal sheet roofs, Table 6.3.5a, 6.3.5b or 6.3.5c; and
    2. for tiled roofs, Table 6.3.5d, 6.3.5e or 6.3.5f.
  2. Effective load widths for structural steel lintels must be determined in accordance with Figure 6.3.5 (a) or (b).
  3. All loads along the structural steel lintel must be evenly distributed.
  4. The top flange of the structural steel lintel must be laterally restrained at the loading points.
  5. Fixing of structural steel lintels must comply with 6.3.7.
  6. Structural steel lintels used in masonry must also comply with H1D5.
  7. Lintel beams must be supported by structural steel columns that comply with 6.3.6.
Table 6.3.5a Maximum lintel span — lintel supporting metal sheet roof, timber floor and 3 m high exterior wall — roof load width = 1.5 m
Section Floor load width (m)
0 1.8 3.6
150 UB 14.0 4.4 3.0 2.5
200 UB 25.4 6.8 4.7 4.0
250 UB 31.4 7.7 5.3 4.6
100 TFB 2.8 1.8 1.5
150 PFC 5.7 3.8 3.2
200 PFC 6.5 4.3 3.7
250 PFC 8.4 5.7 4.9
75 x 75 x 5 EA 2.0 1.0 –
90 x 90 x 6 EA 3.0 1.5 1.0
100 x 100 x 6 EA 3.0 1.8 1.0
125 x 75 x 6 UA 3.0 1.8 1.3
150 x 100 x 10 UA 4.0 3.0 2.5
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 1.16 kN/m permanent wall, 0.4 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Lintels are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A floor load of “0” must be used for lintels not supporting floor loads.
Table 6.3.5b Maximum lintel span — lintel supporting metal sheet roof, timber floor and 3 m high exterior wall — roof load width = 4.5 m
Section Floor load width (m)
0 1.8 3.6
150 UB 14.0 3.1 2.7 2.4
200 UB 25.4 4.9 4.3 3.8
250 UB 31.4 5.6 4.9 4.3
100 TFB 1.9 1.7 1.5
150 PFC 4.0 3.4 3.0
200 PFC 4.5 3.9 3.4
250 PFC 6.0 5.2 4.6
75 x 75 x 5 EA 1.0 – –
90 x 90 x 6 EA 1.8 1.3 –
100 x 100 x 6 EA 1.8 1.3 –
125 x 75 x 6 UA 1.8 1.3 1.0
150 x 100 x 10 UA 3.0 2.5 2.0
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 1.16 kN/m permanent wall, 0.4 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Lintels are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A floor load of “0” must be used for lintels not supporting floor loads.
Table 6.3.5c Maximum lintel span — lintel supporting metal sheet roof, timber floor and 3 m high exterior wall — roof load width = 7.5 m
Section Floor load width (m)
0 1.8 3.6
150 UB 14.0 2.6 2.4 2.2
200 UB 25.4 4.1 3.8 3.6
250 UB 31.4 4.7 4.4 4.1
100 TFB 1.6 1.5 1.4
150 PFC 3.3 3.0 2.8
200 PFC 3.8 3.5 3.3
250 PFC 5.1 4.6 4.3
75 x 75 x 5 EA – – –
90 x 90 x 6 EA 1.0 – –
100 x 100 x 6 EA 1.0 – –
125 x 75 x 6 UA 1.3 1.0 1.0
150 x 100 x 10 UA 2.5 2.0 2.0
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 1.16 kN/m permanent wall, 0.4 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS and G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Lintels are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A floor load of “0” must be used for lintels not supporting floor loads.
Table 6.3.5d Maximum lintel span — lintel supporting tiled roof, tiled floor and 3 m high exterior wall — roof load width = 1.5 m
Section Floor load width (m)
0 1.8 3.6
150 UB 14.0 4.0 2.8 2.3
200 UB 25.4 6.2 4.4 3.7
250 UB 31.4 7.1 5.0 4.3
100 TFB 2.5 1.7 1.4
150 PFC 5.2 3.5 2.9
200 PFC 5.9 4.0 3.4
250 PFC 7.7 5.4 4.5
75 x 75 x 5 EA 2.0 – –
90 x 90 x 6 EA 2.5 1.3 –
100 x 100 x 6 EA 3.0 1.3 –
125 x 75 x 6 UA 2.5 1.5 1.0
150 x 100 x 10 UA 4.0 2.5 2.0
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 1.16 kN/m permanent wall, 0.85 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS G + 0.7Q, G + WS.
  3. 0.9G + WSS for SLS with a maximum deflection of span/300.
  4. Lintels are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A floor load of “0” must be used for lintels not supporting floor loads.
Table 6.3.5e Maximum lintel span — lintel supporting tiled roof, tiled floor and 3 m high exterior wall — roof load width = 4.5 m
Section Floor load width (m)
0 1.8 3.6
150 UB 14.0 2.8 2.5 2.2
200 UB 25.4 4.4 3.9 3.5
250 UB 31.4 5.1 4.5 4.0
100 TFB 1.7 1.5 1.3
150 PFC 3.6 3.1 2.7
200 PFC 4.1 3.6 3.1
250 PFC 5.4 4.7 4.2
75 x 75 x 5 EA – – –
90 x 90 x 6 EA 1.3 1.0 –
100 x 100 x 6 EA 1.5 1.0 –
125 x 75 x 6 UA 1.5 1.0 –
150 x 100 x 10 UA 2.5 2.0 1.8
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 1.16 kN/m permanent wall, 0.85 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Lintels are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A floor load of “0” must be used for lintels not supporting floor loads.
Table 6.3.5f Maximum lintel span — lintel supporting tiled roof, tiled floor and 3 m high exterior wall — roof load width = 7.5 m
Section Floor load width (m)
0 1.8 3.6
150 UB 14.0 2.4 2.2 2.0
200 UB 25.4 3.8 3.4 3.2
250 UB 31.4 4.3 4.0 3.7
100 TFB 1.5 1.3 1.2
150 PFC 3.0 2.7 2.5
200 PFC 3.4 3.1 2.9
250 PFC 4.6 4.2 3.9
75 x 75 x 5 EA – – –
90 x 90 x 6 EA – – –
100 x 100 x 6 EA – – –
125 x 75 x 6 UA 1.0 – –
150 x 100 x 10 UA 2.0 1.8 1.5
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 1.16 kN/m permanent wall, 0.85 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor, positive roof wind pressure of 0.95 kPa and negative roof wind pressure of -1.49 kPa.
  2. Load combinations included are 1.35G, 1.2G + 1.5Q, 1.2G + WU + 0.4Q, 0.9G + WU for ULS G + 0.7Q, G + WS.
  3. 0.9G + WS for SLS with a maximum deflection of span/300.
  4. Lintels are assumed to be partially restrained at both ends with no rotational restraint and are designed as members without full lateral restraint.
  5. A floor load of “0” must be used for lintels not supporting floor loads.
Figure 6.3.5 Lintels supporting roof, frames and timber floors
image-6-3-5-lintels-supporting-roof-frames-and-timber-floors.svg

Structural steel columns must comply with the following:

  1. Columns must support the maximum area provided for in—
    1. Tables 6.3.6a, 6.3.6b and 6.3.6c for columns supporting tiled floor and tiled roof load; and
    2. Tables 6.3.6d, 6.3.6e and 6.3.6f for columns supporting timber floor and metal roof load.
  2. The floor area to be supported is to be determined in accordance with Table 6.3.6g and Figure 6.3.6a.
  3. The flooring system supported by structural steel columns must be fully braced to the footing level either by—
    1. subject to (d), adequately fixing the full height of the column to bracing walls of similar height in the two orthogonal directions of the building; or
    2. a bracing system designed in accordance with AS 1684.2, AS 1684.3, AS/NZS 4600, NASH standard or AS 3700 as appropriate to the materials being used.
  4. For the purposes of (c)(i), the bracing walls must be capable of resisting racking forces in each direction not less than a proportion of the building’s racking force equal to the proportion of floor area that the column is supporting compared to the total floor area of the building.
  5. Acceptable load eccentricity must not exceed 50% of the cross-sectional width plus 100 mm (see Figure 6.3.6b).
  6. Have a minimum nominal yield strength of 250 MPa.
Table 6.3.6a Required column section — columns supporting tiled floor and tiled roof load — roof load area = 0 m2
Column section Effective height (mm) Floor load area (m2)
4 10 16
CHS 250 2400 60.3 x 4.5 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 2700 60.3 x 4.5 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 3000 60.3 x 4.5 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 3300 60.3 x 5.4 CHS 88.9 x 5 CHS 114.3 x 5.4 CHS
CHS 250 3600 60.3 x 5.4 CHS 88.9 x 5 CHS 114.3 x 5.4 CHS
CHS 350 2400 60.3 x 2.9 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 2700 60.3 x 2.9 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 3000 60.3 x 2.9 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 3300 76.1 x 2.3 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 3600 76.1 x 2.3 CHS 101.6 x 2.6 CHS 114.3 x 3.2 CHS
SHS 350 2400 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 2700 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 3000 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 3300 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 3600 65 x 65 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 450 2400 50 x 50 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 2700 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3000 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3300 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3600 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 1.16 kN/m permanent wall, 0.85 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q for ULS.
  3. Columns are assumed to be simply-supported at both ends with an effective length factor of 1.
  4. A maximum load eccentricity of 100 mm has been accounted for in the columns.
  5. A roof load area of “0” must be used for columns not supporting roof loads.
  6. The length of wall load allowed for is equal to the square root of the floor area.
Table 6.3.6b Required column section — columns supporting tiled floor and tiled roof load — roof load area = 9 m2
Column section Effective height (mm) Floor load area (m2)
4 10 16
CHS 250 2400 76.1 x 4.5 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 250 2700 76.1 x 4.5 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 250 3000 76.1 x 5.9 CHS 101.6 x 5 CHS 139.7 x 5 CHS
CHS 250 3300 76.1 x 5.9 CHS 101.6 x 5 CHS 139.7 x 5 CHS
CHS 250 3600 76.1 x 5.9 CHS 101.6 x 5 CHS 139.7 x 5 CHS
CHS 350 2400 76.1 x 3.2 CHS 101.6 x 3.2 CHS 139.7 x 3 CHS
CHS 350 2700 76.1 x 3.2 CHS 101.6 x 3.2 CHS 139.7 x 3 CHS
CHS 350 3000 76.1 x 3.2 CHS 114.3 x 3.2 CHS 139.7 x 3 CHS
CHS 350 3300 88.9 x 2.6 CHS 114.3 x 3.2 CHS 139.7 x 3 CHS
CHS 350 3600 88.9 x 2.6 CHS 114.3 x 3.2 CHS 139.7 x 3 CHS
SHS 350 2400 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 2700 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 3000 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 3300 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 3600 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 2400 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 2700 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3000 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 450 3300 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 450 3600 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 1.16 kN/m permanent wall, 0.85 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor and 0.25 kPa imposed roof.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q for ULS.
  3. Columns are assumed to be simply-supported at both ends with an effective length factor of 1.
  4. A maximum load eccentricity of 100 mm has been accounted for in the columns.
  5. A roof load area of “0” must be used for columns not supporting roof loads.
  6. The length of wall load allowed for is equal to the square root of the floor area.
Table 6.3.6c Required column section — columns supporting tiled floor and tiled roof load — roof load area = 18 m2
Column section Effective height (mm) Floor load area (m2)
4 10 16
CHS 250 2400 88.9 x 5 CHS 114.3 x 5.4 CHS 139.7 x 5 CHS
CHS 250 2700 88.9 x 5 CHS 114.3 x 5.4 CHS 139.7 x 5 CHS
CHS 250 3000 88.9 x 5 CHS 114.3 x 5.4 CHS 139.7 x 5 CHS
CHS 250 3300 88.9 x 5.9 CHS 114.3 x 5.4 CHS 139.7 x 5 CHS
CHS 250 3600 88.9 x 5.9 CHS 114.3 x 5.4 CHS 139.7 x 5 CHS
CHS 350 2400 101.6 x 2.6 CHS 114.3 x 3.6 CHS 139.7 x 3.5 CHS
CHS 350 2700 101.6 x 2.6 CHS 114.3 x 3.6 CHS 139.7 x 3.5 CHS
CHS 350 3000 101.6 x 3.2 CHS 114.3 x 3.6 CHS 139.7 x 3.5 CHS
CHS 350 3300 101.6 x 3.2 CHS 114.3 x 3.6 CHS 139.7 x 3.5 CHS
CHS 350 3600 101.6 x 3.2 CHS 114.3 x 3.6 CHS 139.7 x 3.5 CHS
SHS 350 2400 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS 100 x 100 x 4 SHS
SHS 350 2700 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS 100 x 100 x 4 SHS
SHS 350 3000 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS 100 x 100 x 5 SHS
SHS 350 3300 100 x 100 x 3 SHS 100 x 100 x 4 SHS 100 x 100 x 5 SHS
SHS 350 3600 100 x 100 x 3 SHS 100 x 100 x 4 SHS 100 x 100 x 5 SHS
SHS 450 2400 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 2700 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 3000 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 3300 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 3600 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
Table Notes
  1. Load accounted for includes 0.98 kPa permanent floor, 1.16 kN/m permanent wall, 0.85 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor and 0.25 kPa imposed roof.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q for ULS.
  3. Columns are assumed to be simply-supported at both ends with an effective length factor of 1.
  4. A maximum load eccentricity of 100 mm has been accounted for in the columns.
  5. A roof load area of “0” must be used for columns not supporting roof loads.
  6. The length of wall load allowed for is equal to the square root of the floor area.
Table 6.3.6d Required column section — columns supporting timber floor and metal roof load — roof load area = 0 m2
Column section Effective height (mm) Floor load area (m2)
4 10 16
CHS 250 2400 60.3 x 3.6 CHS 76.1 x 5.9 CHS 101.6 x 5 CHS
CHS 250 2700 60.3 x 3.6 CHS 76.1 x 5.9 CHS 101.6 x 5 CHS
CHS 250 3000 60.3 x 4.5 CHS 76.1 x 5.9 CHS 101.6 x 5 CHS
CHS 250 3300 60.3 x 4.5 CHS 76.1 x 5.9 CHS 101.6 x 5 CHS
CHS 250 3600 60.3 x 4.5 CHS 88.9 x 5 CHS 101.6 x 5 CHS
CHS 350 2400 60.3 x 2.3 CHS 88.9 x 2.6 CHS 101.6 x 3.2 CHS
CHS 350 2700 60.3 x 2.9 CHS 88.9 x 2.6 CHS 114.3 x 3.2 CHS
CHS 350 3000 60.3 x 2.9 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 3300 60.3 x 2.9 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 3600 60.3 x 2.9 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
SHS 350 2400 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 350 2700 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 350 3000 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 350 3300 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 350 3600 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 2400 50 x 50 x 2 SHS 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS
SHS 450 2700 50 x 50 x 2 SHS 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS
SHS 450 3000 50 x 50 x 2 SHS 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS
SHS 450 3300 50 x 50 x 2.5 SHS 89 x 89 x 3.5 SHS 89 x 89 x 3.5 SHS
SHS 450 3600 50 x 50 x 2.5 SHS 89 x 89 x 3.5 SHS 89 x 89 x 3.5 SHS
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 1.16 kN/m permanent wall, 0.4 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor and 0.25 kPa imposed roof.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q for ULS.
  3. Columns are assumed to be simply-supported at both ends with an effective length factor of 1.
  4. A maximum load eccentricity of 100 mm has been accounted for in the columns.
  5. A roof load area of “0” must be used for columns not supporting roof loads.
  6. The length of wall load allowed for is equal to the square root of the floor area.
Table 6.3.6e Required column section — columns supporting timber floor and metal roof load — roof load area = 9 m2
Column section Effective height (mm) Floor load area (m2)
4 10 16
CHS 250 2400 60.3 x 5.4 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 2700 76.1 x 3.6 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 3000 76.1 x 3.6 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 3300 76.1 x 3.6 CHS 88.9 x 5 CHS 114.3 x 4.5 CHS
CHS 250 3600 76.1 x 4.5 CHS 88.9 x 5.9 CHS 114.3 x 5.4 CHS
CHS 350 2400 76.1 x 2.3 CHS 88.9 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 2700 76.1 x 2.3 CHS 101.6 x 2.6 CHS 114.3 x 3.2 CHS
CHS 350 3000 76.1 x 3.2 CHS 101.6 x 2.6 CHS 114.3 x 3.2 CHS
CHS 350 3300 76.1 x 3.2 CHS 101.6 x 3.2 CHS 114.3 x 3.2 CHS
CHS 350 3600 76.1 x 3.2 CHS 101.6 x 3.2 CHS 114.3 x 3.2 CHS
SHS 350 2400 65 x 65 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 2700 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 3000 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 3300 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 4 SHS
SHS 350 3600 75 x 75 x 2.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 2400 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 2700 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3000 65 x 65 x 2 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3300 65 x 65 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3600 65 x 65 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 1.16 kN/m permanent wall, 0.4 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor and 0.25 kPa imposed roof.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q for ULS.
  3. Columns are assumed to be simply-supported at both ends with an effective length factor of 1.
  4. A maximum load eccentricity of 100 mm has been accounted for in the columns.
  5. A roof load area of “0” must be used for columns not supporting roof loads.
  6. The length of wall load allowed for is equal to the square root of the floor area.
Table 6.3.6f Required column section — columns supporting timber floor and metal roof load — roof load area = 18 m2
Column section Effective height (mm) Floor load area (m2)
4 10 16
CHS 250 2400 76.1 x 4.5 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 250 2700 76.1 x 5.9 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 250 3000 76.1 x 5.9 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 250 3300 76.1 x 5.9 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 250 3600 76.1 x 5.9 CHS 101.6 x 5 CHS 114.3 x 5.4 CHS
CHS 350 2400 76.1 x 3.2 CHS 101.6 x 3.2 CHS 114.3 x 3.6 CHS
CHS 350 2700 76.1 x 3.2 CHS 101.6 x 3.2 CHS 114.3 x 3.6 CHS
CHS 350 3000 88.9 x 2.6 CHS 101.6 x 3.2 CHS 114.3 x 3.6 CHS
CHS 350 3300 88.9 x 2.6 CHS 101.6 x 3.2 CHS 114.3 x 3.6 CHS
CHS 350 3600 88.9 x 2.6 CHS 101.6 x 3.2 CHS 114.3 x 3.6 CHS
SHS 350 2400 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 2700 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 3000 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 3300 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 350 3600 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS 100 x 100 x 4 SHS
SHS 450 2400 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 2700 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3000 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3300 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
SHS 450 3600 75 x 75 x 2.5 SHS 89 x 89 x 3.5 SHS 100 x 100 x 3 SHS
Table Notes
  1. Load accounted for includes 0.53 kPa permanent floor, 1.16 kN/m permanent wall, 0.4 kPa permanent roof, permanent member self-weight, 1.5 kPa or 1.1 kN imposed floor and 0.25 kPa imposed roof.
  2. Load combinations included are 1.35G and 1.2G + 1.5Q for ULS.
  3. Columns are assumed to be simply-supported at both ends with an effective length factor of 1.
  4. A maximum load eccentricity of 100 mm has been accounted for in the columns.
  5. A roof load area of “0” must be used for columns not supporting roof loads.
  6. The length of wall load allowed for is equal to the square root of the floor area.
Table 6.3.6g Area supported by columns
Column descriptor (as shown in Figure 6.3.6a) Total area supported
C1 0.4L1 x 0.4LA
C2 0.7(L1 + L2) x 0.4LA
C3 0.4L1 x 0.7(LA + LB)
C4 0.7(L1 + L2) x 0.7(LA + LB)
C5 0.4L1 + 0.4LC
C6 0.7(L1 + L2) x 0.4LC
Table Notes

The total area supported equations marginally overestimate the total area to account for a difference between L1 and L2 by up to 30%.

Figure 6.3.6a Determining floor area supported by columns
image-6-3-6a-determining-floor-area-supported-by-columns.svg
Figure 6.3.6b Acceptable load eccentricity for columns
image-6-3-6b-acceptable-load-eccentricity-for-columns.svg

Explanatory information: Cantilever columns

A cantilever column is not assisted by any lateral bracing element such as a column bracing set, timber or masonry wall.

Explanatory information: Calculating column size

The following is an example of the steps required to calculate a suitable column to support typical floor loads in a residential building. It is proposed the column will—

  • have an actual height of 1800 mm; and
  • support a timber floor only; and
  • be square in section; and
  • be cast in to the footings; and
  • be fully braced by column bracing sets.

Step 1 – Determining effective column height

The column height (H) is determined by multiplying the actual height by the relevant height factor (F1) in Tables 6.3.6d, 6.3.6e or 6.3.6f. In this case, the relevant value for F1 is 1.00 as the column is cast in to the footing and is fully braced.

Therefore:

  • H = actual height x F1
  • H = 1800 mm x F1
  • H = 1800 mm (1.8 m)

Step 2 – Determine floor area to be supported

The column position selected is C4 as shown in Figure 6.3.6a and the dimensions of L1 and L2 are 2700 mm (2.7 m), LA is 1900 mm (1.9 m) and LB is 2100 mm (2.1 m).

The area supported by the column is determined by the formulae set out in Table 6.3.6g.

Therefore:

  • Total area supported (A) is 0.625(L1 + L2) x 0.625(LA + LB)
  • A = 0.625(2.7 m + 2.7 m) x 0.625 x (1.9 m + 2.1 m)
  • A = (0.625 x 5.4 m) x (0.625 x 4.0 m)
  • A = 3.38 m x 2.5 m
  • A = 8.5 m2

Step 3 – Select column size from Tables 6.3.6d, 6.3.6e or 6.3.6f

The column with an effective height of 1800 mm supporting a floor area of 8.5 m2 is selected from the 10 m2 column in Table 6.3.6d (“0” roof load area) giving a SHS 350 75 x 75 x 3 size.

It should be noted there is a choice of CHS 250 88.9 x 4 or CHS 350 101.6 x 2.6 should a different section be desired.

(1) All bolts used in connections must be hot dip galvanised 300 g/m2.

(2) Bearer connections must be fixed in accordance with Figure 6.3.7a.

(3) Joists, bearers and lintels must be restrained from lateral movement or twisting along their length by fixing rafters or joists to the top flange of the member so as to prevent the member from moving laterally.

(4) End supports for bearers and lintels must transfer loads to the footings and have a bearing distance as follows:

  1. For single spans, the bearing distance must be not less than the width of the member.
  2. For continuous spans, internal bearing must be not less than two times the width of the member.

(5) Strutting beams must—

  1. be supported and fixed in accordance with Figure 6.3.7b; and
  2. where ends are cut to suit roof pitch, be cut in accordance with Figure 6.3.7c.

(6) Lintels must be fixed in accordance with Figures 6.3.7d, 6.3.7e, 6.3.7f, 6.3.7g and 6.3.7h.

Figure 6.3.7a Bearer supporting a timber floor and non-loadbearing stud wall
image-6-3-7a-bearer-supporting-timber-floor-and-non-loadbearing-stud-wall.svg
Figure 6.3.7b Strutting beam supporting roof and ceiling
image-6-3-7b-strutting-beam-supporting-roof-and-ceiling.svg
Figure 6.3.7c End cuts to strutting beams
image-6-3-7c-end-cuts-to-strutting-beams.svg
Figure Notes

Strutting beam top plate to be tied down in accordance with 6.3.4.

Figure 6.3.7d Lintels supporting roof, frames and timber floors
image-6-3-7d-lintels-supporting-roof-frames-and-timber-floors.svg
Figure 6.3.7e Lintels supporting roof, frames and timber floors — sections
image-6-3-7e-lintels-supporting-roof-frames-and-timber-floors-section.svg
Figure 6.3.7f Typical universal beam to column connection detail
image-6-3-7f-typical-universal-beam-to-column-connection-detail.svg
Figure Notes
  1. 8 mm steel plates to be welded to the top and bottom of the column using 5 mm fillet welds.
  2. Plate width must be the greater of the column width or the beam width.
  3. Plate length must be such that there is not less than 40 mm from the centreline of the bolts to the ends.
  4. All bolting between structural steel members must be not less than 2 M12 4.6/S.
Figure 6.3.7g Typical PFC and RHS beam to column connection detail
image-6-3-7g-typical-PFC-and-RHS-beam-to-column-connection-detail.svg
Figure 6.3.7h Typical column base plate detail
image-6-3-7h-typical-column-base-plate-detail.svg
Figure Notes

Fixing of the column base plate to the slab must be not less than 2 M12 4.6/S post-installed mechanical anchors.

Explanatory information

The ends of bearers and lintels must be sufficiently supported to ensure structural loads are transferred to the footing system. The amount of horizontal bearing (measured in millimetres) required on the vertical supports will depend on the type of span of the bearer or lintel. For single spans, the amount of horizontal bearing is to be equal to or greater than the width of the bearer or lintel. For continuous spans it is to be twice the width of the bearer or lintel.

For bearing distance, see 6.3.7(4)(a) and (b).

Explanatory Figure 6.3.7 depicts an example of a 200 PFC bearer or lintel supporting floor or roof loads over a single span.

Figure 6.3.7 (explanatory) Example of a 200 PFC bearer or lintel supporting floor or roof loads over a single span
image-6-3-7-explanatory-example-200-PFC-bearer-lintel-supporting-floor-or-roof-loads-over-single-span.svg

Penetrations through structural steel members must be within the allowable zones in Figure 6.3.8.

Figure 6.3.8 Allowable zones for penetrations through structural steel members
image-6-3-8-allowable-zones-for-penetrations-through-structural-steel-members.svg

Explanatory information

Cutting and penetrations in structural steel should be avoided where possible. Figure 6.3.8 provides permissible zones for penetrations through structural steel. However, it is recommended that a suitable qualified professional be consulted where penetrations or cuts are required to be made on site.

Structural steel members that are not built in to a masonry wall must—

  1. be protected against corrosion in accordance with Tables 6.3.9a, 6.3.9b and 6.3.9c; and
  2. where a paint finish is applied to the surface, be free from rust; and
  3. where zinc coatings are applied to the surface, be provided with a barrier coat to prevent domestic enamels from peeling; and
  4. when cut or welded on-site, have those areas and any other areas of damage to protective coatings comply with (a).
Table 6.3.9a Minimum protective coatings for structural steel members
Environment Location Minimum protective coating
Option 1 (hot dip galvanising) Option 2 (duplex system). See Table 6.3.9c Option 3 (paint). See Table 6.3.9b
Low (mild steel corrosion rate 1.3 to 25 μm/year Typically remote inland areas or more than 1 km from sheltered bays HDG75 – ACL2, ACC2, IZS1, PUR2A
Medium (mild steel corrosion rate 25 to 50 μm/year) Typically more than 1 km from breaking surf or aggressive industrial areas or more than 50 m from sheltered bays HDG225 – ACL3, ACC4, ACC5, IZS1, PUR3, PUR4
High (mild steel corrosion rate 50 to 80 μm/year) Typically more than 200 m from breaking surf or aggressive industrial areas or within 50 m from sheltered bays HDG450 HDG150 (5 years) 4D (10-15 years) or HDG300 (10 years) 2D (5-10 years) ACC6, IZS3, PUR5
Very High (mild steel corrosion rate 80 to 200 μm/year) Typically extends from 100 m inland from breaking surf to 200 m inland from breaking surf, or within 200 m of aggressive industrial areas and within 100 m of breaking surf. HDG900 HDG300 (5 years) 5D (10-15 years) or HDG600 (10 years) 4D (5-10 years) ACC6 (C5-M only), PUR5
Table Notes

Hot dip galvanising and duplex systems must be in accordance with AS 2312.2. Paint systems must be in accordance with AS 2312.1.

Table 6.3.9b Paint coating system specification
AS 2312.1 system Surface preparation 1st coat 2nd coat 3rd coat Total DFT
Type of paint DFT Type of paint DFT Type of paint DFT
ACC2 Sa 2.5 Epoxy primer 75 Acrylic (2 pack) 50 – – 125
ACC4 Sa 2.5 Epoxy primer 75 High build epoxy 125 Acrylic (2 pack) 50 250
ACC5 Sa 2.5 Zinc rich primer 75 High build epoxy 125 Acrylic (2 pack) 50 250
ACC6 Sa 2.5 Zinc rich primer 75 High build epoxy 200 Acrylic (2 pack) 50 325
ACL2 Sa 2.5 Zinc rich primer 75 Acrylic latex 40 Acrylic latex 40 155
ACL3 Sa 2.5 Zinc rich primer 75 High build epoxy 125 Acrylic latex 40 240
IZS1 Sa 2.5 Inorganic zinc silicate 75 – – – – 75
IZS3 Sa 2.5 Inorganic zinc silicate 125 – – – – 125
PUR2A Sa 2.5 Zinc rich primer 75 High build polyurethane 75 – – 150
PUR3 Sa 2.5 Epoxy primer 75 High build epoxy 125 Polyurethane gloss 50 250
PUR4 Sa 2.5 Zinc rich primer 75 High build epoxy 125 Polyurethane gloss 50 250
PUR5 Sa 2.5 Zinc rich primer 75 High build epoxy 200 Polyurethane gloss 50 325
Table Notes

DFT refers to dry film thickness, measured in μm.

Table 6.3.9c Duplex coating system specification
AS 2312.2 duplex system Surface preparation 1st coat 2nd coat 3rd coat Total DFT
Type of paint DFT Type of paint DFT Type of paint DFT
2D Degrease, wash and dry, sweep blast clean Epoxy primer (2 pack) inhibitive 75 Polyurethane or acrylic gloss (2 pack) 100 – – 175
4D Degrease, wash and dry, sweep blast clean High-build epoxy (2 pack) 250 Polyurethane or acrylic gloss (2 pack) 100 – – 350
5D Degrease, wash and dry, sweep blast clean Epoxy primer (2 pack) inhibitive 75 High-build epoxy (2 pack) 225 Polyurethane or acrylic gloss (2 pack) 100 400
Table Notes

DFT refers to dry film thickness, measured in μm.

Notes

Clause 3.4.4.4 and Table 3.4.4.7 from NCC Volume Two 2019 (Amendment 1) may be used in place of 6.3.9 and Tables 6.3.9a, 6.3.9b and 6.3.9c until 1 May 2024.