Load Analysis & Structural Modelling
Gravity loads are determined in accordance with AS/NZS 1170.1, with wind pressures calculated to AS/NZS 1170.2 using site-specific terrain and shielding parameters. Where the project is located in a seismic zone, earthquake actions are assessed to AS 1170.4. Load combinations follow AS/NZS 1170.0. For multi-storey LGS structures or where load paths are non-obvious, we develop a structural model to verify load distribution before proceeding to member design.
Wall Frame Design
Stud design covers axial compression, combined bending and compression under eccentric load application, and web crippling at bearing locations. Track members are checked for combined bending and bearing. Stud-to-track connections are detailed with screw patterns sized for the calculated shear demand. Where jamb studs or built-up sections are required at openings or high-load locations, these are designed and specified explicitly.
Shear wall design follows the NASH Standard sheathing contribution methodology or first-principles strap bracing design, depending on what is appropriate for the structural system. Chord stud uplift and hold-down anchor forces are calculated and reported for use in the footing design.
Floor Cassette Design
LGS floor joists are designed for flexure, shear, web crippling at supports, and deflection under serviceability loads. We check both short-term deflection under imposed load and long-term deflection inclusive of dead load and any relevant creep factor. Where span-to-depth ratios or loading conditions suggest a risk of floor vibration, we assess dynamic performance in accordance with the AISC Design Guide 11 methodology, adapted for LGS sections.
Bridging requirements are determined from the compression flange restraint analysis and specified at calculated intervals, not defaulted to a standard spacing.
Roof Truss Design
Cold-formed LGS trusses are analysed as pin-jointed planar frames under the governing load combinations. Top chord design accounts for bending between panel points where the purlin layout does not provide full restraint at each node. Bottom chord tension design includes net section reduction at screw connections. Web members are checked for both tension and compression, with effective length determined from the connection geometry and any intermediate restraints provided by the truss bracing system.
Connection Design & Documentation
All connections are designed for the calculated design actions and documented with screw quantity, pattern, and spacing. Hold-down strap ties are sized for the calculated net uplift force including the applicable load combination factor. Baseplate and anchor bolt connections to concrete or masonry substrates are designed to AS 3600 or AS 3700 as applicable. Connection details are drawn up and included in the structural drawings, not left to the builder’s discretion.
Structural Certificates & Reporting
We issue certificates of structural adequacy for building permit and DA submissions, signed and sealed by a Registered Structural Engineer (RPEQ/NER). Certificates reference the applicable design standards, describe the scope of assessment, and identify any conditions or limitations. We also prepare structural reports for peer review, building surveyor queries, and insurance assessments.
Design Documentation Package
Standard deliverables for an LGS structural design engagement include:
Applicable Standards
