Truss Fabrication Guide: Types & Applications
Quick Answer
Common industrial truss types include Pratt, Warren and Howe trusses, each optimizing member arrangement for different span-to-load ratios — the right choice depends on span length, applied load pattern and, for PEB structures, is typically determined by the structural design software rather than selected manually.
Why Trusses Instead of Solid Beams
For long spans, a truss (an open framework of triangulated members) carries the same load with significantly less steel than a solid beam, because load is distributed through axial tension and compression in the members rather than bending — this is why trusses are the standard solution for wide-span industrial roofs.
Common Truss Configurations
- Pratt truss — diagonal members in tension, vertical members in compression; efficient for many standard span/load combinations
- Warren truss — alternating diagonal members without verticals, often used where a lighter overall structure is prioritized
- Howe truss — the reverse configuration of Pratt, sometimes preferred for specific load direction scenarios
Fabrication Considerations
Truss fabrication requires precise joint alignment since load paths depend on accurate geometry — even small fabrication errors at joints can meaningfully affect a truss's actual load-carrying capacity, which is why shop-controlled fabrication with proper jigging matters more for trusses than for simpler structural elements.