Wood Truss Bracing Rules Updated

[Frank Woeste]

Once state codes or local jurisdictions adopt the 2009 International Building Code (IBC), Owners of a project with metal-plate-connected (MPC) wood trusses will be required to engage a registered professional to design and inspect both temporary and permanent bracing for such trusses when spanning 60 ft and greater.

The effectiveness of this code change on life safety will likely be conditioned on education of design professionals and especially awareness of the building code community.

To view the entire article that was published in the Construction Specifier, please visit this site starting at page 54:

http://www.kenilworth.com/publications/cs/de/201105/index.html

Thank you, Frank

Frank Woeste, Ph.D., P.E.

Professor Emeritus

Virginia Tech University

 

[Francis Vineyard]

Frank,

Good information to pass on to local RDP's

2303.4.1.3 Trusses spanning 60 feet or greater. The owner shall contract with any qualified registered design professional for the design of the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing for all trusses with clear spans 60 feet or greater.

Thanks,

Francis

 

[Mark K]

It is my understanding that building departments do not have jurisdiction to regulate safety during construction rather they regulate the safety of the completed building. This is because OSHA has primary jurisdiction. Thus it is suggested that regulations related to temporary bracing such as temporary truss bracing are invalid.

The code provisions related to long trusses were promoted by the truss industry as a way to shift liability to the Owner. What other reason is there for requiring that the Owner be responsible for the design of the temporary bracing?

There is no question that temporary bracing is necessary. The question is whether this provision is legal and if it is whether it is good policy. My preference is for the entity who decides the sequence of construction to take responsibility for the temporary bracing.

We should ask the question are the provisions in the IBC compatible with the authority of the jurisdictions adopting them.

 

[Francis Vineyard]

The code change correlates with the updated TPI-2007 referenced in 2009 IBC. My guess because the temporary bracing practices have resulted in not only failures during installation but compromise the reliability of the final assembly.

http://www.structuremag.org/Archives/2009-8/D-CodeUpdates-Woeste-Aug09.pdf

The commentary link did not work for me at the end of the aforementioned article. Another article; http://www.structuremag.org/article.aspx?articleID=603

The new special inspections required adds a degree of consistency for the RDP requirement of these larger trusses; http://media.iccsafe.org/news/eNews/2010v7n8/codeupdate-ibc.pdf

Francis