This article appeared in the 2012 May issue and was authored by Larry Wainright, Ryan Dexter, P.E., Jim Vogt, P.E. & Kirk Grundahl, P.E..
- Based on the recommendations of the IRC, IBC and ASCE 7, truss or rafter uplift connections should be designed for applied wind loads using MWFRS analysis.
- Individual truss and rafter members should be designed using C&C generated wind loads.
- The SBCA Load Guide includes information about uplift connections for structural building components.
This article appeared in the 2012 April issue and was authored by Tony Piek.
- In addition to implementing a QC program and training staff, another good way to increase awareness of quality control issues is by creating QC posters strategically placed throughout the shop floor.
- A QC board can use photos or actual material examples to illustrate common QC dos and don’ts.
- Work is underway to revise and reaffirm Chapter 3 of the ANSI/TPI 1 standard on quality control.
This article appeared in the 2012 March issue and was authored by SBC Staff.
- Two engineers involved in the design of structural building components respond to a previous Technical Q&A on bearing area.
- Both give their perspective on bearing area and ways that component manufacturers and truss designers can help engineers with this issue.
- Each engineer discusses his preferred method for dealing with insufficient bearing area.
This article appeared in the 2012 January/February issue and was authored by SBC Staff.
- Be proactive and develop a plan to strategize how you might deal with a truss collapse and the subsequent investigation.
- Information is critical; visit the site, take lots of photos and document as much as you can.
- Remember that the only company looking out for your company’s best interests is your own. Take action with this in mind, and ultimately, it will save everyone money and time.
This article appeared in the 2011 December issue and was authored by Ryan J. Dexter, P.E. & Larry Wainright.
- Only scaffold-grade lumber should be used for erecting scaffolds.
- Scaffold-grade lumber meets strength criteria determined by the grading rules set by a recognized lumber grading agency or independent lumber inspection agency and meet the minimum requirements of OSHA standard 29 CFR 1926.
- The characteristics required for scaffold-grade lumber, such as number and size of knots, slope of grain and juvenile wood, are higher and more stringent than those for construction lumber.
This article appeared in the 2011 November issue and was authored by SBCA Staff.
- The Building Designer providing accurate wall or beam/header information in the Construction Documents is essential in order for the Truss Designer to arrive at the correct bearing width.
- There are two key bearing related considerations—bearing capacity of the truss and bearing capacity of what the truss is sitting on; often, the bearing capacity of this material is an unknown and an assumption must be made.
- The options for dealing with insufficient bearing need to be considered and specifically dealt with on a case-by-case basis.
This article appeared in the 2011 August issue and was authored by Jim Vogt, P.E..
- Plywood and OSB design values are given; those that are doing repairs in your office should have a good feel for the similarities and differences.
- Plywood and OSB generally have similar design properties with a key exception of fastener strength where plywood will require more fasteners to be used.
- If a truss repair specifies only OSB, plywood should not be substituted without written permission from the registered design professional who prepared the truss repair design drawing.
This article appeared in the 2011 June/July issue and was authored by Jim Vogt, P.E..
- The strength axis of a structural panel is the direction parallel to the grain of the wood fiber in the face and back surfaces of the panel.
- The strength axis is usually the long dimension of the panel.
- The IBC provides two tables with the allowable spans and loads (psf) for wood structural panel sheathing installed continuous over two or more spans with their strength axis perpendicular and parallel to the supports.
This article appeared in the 2011 Sept/Oct issue and was authored by Jim Vogt, P.E. & Larry Wainright.
- The Occupancy Category designates the nature of occupancy for a building, which affects the required design loads for the structure.
- There is a direct relationship between the Occupancy Category and the Importance Factor—a low category will result in lower loads and a high category will call for an increase in loads
This article appeared in the 2011 May issue and was authored by Ryan Dexter.
- Every component design department should have a small reference library of important technical documents.
- It is generally best to make sure your designs conform with the most current versions of the IBC and IRC.
- However, building code adoption is at the discretion of the authority having jurisdiction.
