Bracing & Restraint

A full-scale truss bracing demo was an eye-catching feature of the BCMC 2017 show floor.

If you’ve been in the truss industry for any length of time, there’s one phone call you absolutely dread receiving: “We have a problem; your trusses collapsed!”

Is it common practice for the supplier/distributor of a truss to provide a publication regarding temporary bracing with the delivery of the material?

Are there any schematics available on how to horizontally brace a 7/12 pitch roof?

I am a building inspector and have some questions regarding how to apply IBC 2012 2308.8.5 (IRC 2012 R802.8) (similar IBC 2015 2308.4.6 & IRC 2015 R802.8) to trusses, especially those with high heels:

What are the requirements on the permanent bracing of bottom chords? Can gypsum board diaphragms be used?

What are the requirements for installing “valley set” overlay roof trusses? I am interested in nailing and support conditions. Some engineers ask for the bottom chord of the valley truss to be ripped to match the roof pitch of the underlying trusses. Is this necessary?

How important is continuous lateral bracing in roof trusses? Is it detrimental to the roof integrity if it is missing?

I almost always see wood trusses erected with no stability bracing at points of support. It seems to me that common sense and section 3.3.3.4 of The American Wood Council’s National Design Specification for Wood Construction (NDS) require that lateral support be provided at points of bearing. Plywood decking doesn't provide any more restraint for a wood truss than it does for a roof joist. I doubt if it was a concern with short span trusses having 4 in.

What are the requirements for installing valley sets over roof trusses? I am interested in nailing and support conditions. Some engineers ask for the bottom chord of the valley truss to be ripped to match the roof pitch of the underlying trusses. Is this necessary? How can I calculate values for uplift resistance for the building inspector?