Roof Truss Bracing

This photo was taken about 10 Seconds Before The 52’ Scissor Trusses Collapsed. There was no Wind Load. The Top Chord is Buckling from a LACK OF PROPER TOP CHORD BRACINGDan Smith has investigated a variety of roof structure collapses and
finger pointing in the construction industry.

The Wood Truss Council of America and the Truss Plate Institute developed the ANSI/TPI
specification for truss designed and added a section on Design Responsibility. Some Architects and structural engineers immediately disagreed with the main point of this section, which placed the bracing responsibility on the designers (Architects and Structural Engineers), and not the truss manufacturers and their engineers and designers.

There is a disagreement in the design world about who is responsible for the truss bracing. The truss manufacturers do not design buildings, so they feel that they are not legally allowed to design the bracing nor do they have the knowledge of the building design to transfer lateral truss forces to building components.

Likewise the architects and structural engineers are not familiar enough with a specialized product (such as wood trusses, metal trusses, cold formed metal studs) which all have unique bracing and sheathing and loading requirements. In addition to buckling and wide variety of species and lumber grades (likewise steel specifications and yields). The architects and engineers do not feel like they know enough about the specific problem to adequately design a bracing plan.

Both sides are in need of an experienced bracing design engineers, with building design expertise...

The 2006 International Building Code now requires a bracing design professional for roof truss installations over 60 feet in clear span. Paul and I would recommend a bracing professional for scissor or flat roof trusses spanning over 55 feet.  Read more about the impact of these new regulations in our article section.