Lateral Systems in Multi-Storey Light Steel Frame: Who Engineers Them

Gravity is the easy part of a steel-framed building. The harder part is keeping it from racking sideways in wind or an earthquake. In multi-storey buildings the lateral system usually governs the wall design, the connections and sometimes the foundations.

Common lateral systems

• Sheathed shear walls: structural sheathing fixed to the steel studs with a tested fastener pattern. See shear wall.
• Strap-braced walls: flat steel straps in an X pattern, sized for tension, with strong end posts and anchors.
• Diaphragms: floors and roofs that carry the load to the walls. Their stiffness depends on the floor system.
• Hybrid designs: steel or concrete cores and podiums combined with light steel frame walls above.

Where it goes wrong

Lateral performance is only as good as its details: hold-downs, anchors, strap connections and fastener spacing. Missing a fastener schedule, or substituting a different screw, can invalidate a calculation. See fasteners and connectors documentation.

Who must engineer it

The engineer of record for the building is responsible for the lateral system and signs the drawings that go to the permit office. Some supply contracts include delegated design, where the supplier's engineer designs the framing to the architect and engineer of record's criteria. Know which arrangement you have. For roles, read architect vs designer vs engineer.

Questions for any supplier

• Is the design stamped, and by whom, in which jurisdiction?
• Which standard and code edition does it use?
• Is there a test report for the sheathing and fastener combination?
• Who supplies hold-downs and anchors, and are they in the quote?

Where Digital Oro fits

The catalog describes framing material and components, not a lateral design for your building. Digital Oro International lists light steel frame in its material catalog: structural frame in AS1397 G550 AZ150 steel (0.75 or 0.95 mm), available in Australian or American standards, plus wall frames with glass wool, 89 mm x 41 mm pre-assembled floor joists, roof trusses and subfloor systems. See the light steel frame catalog page and the full catalog map. The catalog gives specifications only. It does not give prices, lead times, stock or project references, so none are stated here.

Ask Digital Oro in writing: whether it provides engineered shear wall or bracing designs, or only framing components to your engineer's design; what fasteners and connectors are included; the steel grade and coating certificates; and the standard (AS or ASTM) used.

This guide is general information, not engineering, legal or financial advice. Codes, loads and approvals vary by site; the engineer of record and the local authority decide what your building needs.

Questions people ask

What is a lateral system?

The part of the structure that resists sideways forces from wind and earthquakes, typically shear walls or braced frames, tied together by floor diaphragms.

Who designs it?

A licensed structural engineer of record for the project, not the material supplier by default.

What is a shear wall?

A wall designed to resist in-plane lateral force. See the glossary entry on shear walls.

Is a seismic standard involved?

In seismic regions designers commonly use AISI S400, the North American standard for seismic design of cold-formed steel structural systems, together with the adopted building code.

Sources and further reading

• AISI, American Iron and Steel Institute
• Steel Framing Industry Association (SFIA)
• International Code Council

Text Digital Oro

Digital Oro International advertises on The Company Chronicle. This guide was written by our editorial team from public sources and general professional practice; it does not describe a guarantee, quote or offer from Digital Oro International. Confirm current terms, prices and availability with the operator before you decide.