Primary Framing
Primary Framing Systems for Pre-Engineered Buildings
Primary framing systems from World Steel: clear-span, multi-span, single-slope and lean-to rigid frames designed to US, Canadian, Australian or European codes.
Key features
- Clear-span, multi-span, single-slope, lean-to and multi-gable frame types
- Tapered built-up members optimized for the bending moment
- Bolted end plate connections for fast site assembly
- Rigid or post-and-beam endwalls, including expandable endwalls
- Designed together with cranes, mezzanines and canopies
- Calculations, anchor bolt plans and erection drawings supplied
The primary framing system is the backbone of a pre-engineered building. It consists of the main rigid frames, interior columns, endwall frames and the bolted connections that join them, and it carries roof, wall, crane and mezzanine loads down to the foundations. World Steel designs and supplies complete primary framing packages engineered to the code specified for the project, including US, Canadian, Australian and New Zealand, and European codes.
Frames are configured to suit the building rather than chosen from a fixed catalog. Clear-span frames give column-free interiors for warehouses, hangars and sports halls. Multi-span frames with interior columns cover very wide buildings economically. Single-slope and lean-to frames suit carports, annexes and buildings next to existing structures, while multi-gable frames cover large areas with a series of ridges.
Each member is typically a built-up I-section, tapered where it helps to follow the bending moment, so that steel is used where it is needed. Endwalls can be framed as post-and-beam systems for economy or as full rigid frames where future expansion or large openings are planned. Connections are usually bolted end plates, which keep site work to bolting and allow fast, accurate erection.
The project engineer sets frame spacing, depth, bracing and deflection limits from the loads and code for the site, and confirms every design decision in the calculation package. Shop drawings, anchor bolt plans and erection drawings are issued with the steel so the contractor has everything needed to set out foundations and assemble the frames.
Primary framing can be combined with cranes, mezzanines, canopies and roof extensions from the same design package, which keeps loads, connections and interfaces coordinated across the whole building.
When requesting a quotation, state the building dimensions, frame type preference, governing code, site loads, any cranes or mezzanines, and the finish required. The project engineer then confirms the most economical frame arrangement for those conditions.
Specification
| Frame types | Clear-span, multi-span, single-slope, lean-to, multi-gableSelected for the building use and layout |
|---|---|
| Member type | Built-up welded I-sections, tapered or prismaticHot-rolled sections where suitable |
| Span and bay spacing | Project specificSet by the project engineer for loads and economy |
| Steel grades | Structural plate and sections to ASTM, CSA, AS/NZS or EN standardsGrade selected by design and project specification |
| Connections | Bolted end plate and splice connectionsBolt type and tightening per the governing code |
| Surface finish | Primer, paint system or hot-dip galvanizingChosen for exposure and durability |
| Design codes | US, Canadian, Australian/New Zealand or EuropeanAs specified for the project |
Engineering content is general guidance. Every World Steel building is designed by qualified engineers to the code and loads of the project.
