The Southern Pine Inspection Bureau (SPIB) issued new design values effective June 1, 2012 inSupplement No.9 to the 2002 Standard Grading Rules for Southern Pine Lumber. The only design values that changed apply to visually graded Southern Pine and Mixed Southern Pine sized 2” to 4” wide and 2” to 4” thick (2x2s through 4x4s) in No.2 and lower grades (No.2, No.3, Stud, Construction, Standard and Utility). This also includes new design values for No.2 Dense and No.2 NonDense Southern Pine. Design values for all other grades and sizes of visually graded Southern Pine remain the same, pending results of testing scheduled for completion later this year.
Many producers and key customer groups have already successfully transitioned to the new design values with minimal disruption to their businesses. Now that June 1 is here, Southern Pine users should begin using the new design values and revised span tables for new construction if they haven’t done so already.
Building codes reference design values certified by the ALSC Board of Review. The American Wood Council (AWC) publishes these design values in a supplement to the code-referenced National Design Specification® (NDS®) for Wood Construction. Building codes also include span tables and other prescriptive requirements that need to be amended to reflect the new design values. Visit www.awc.orgto download the AWC Addendum to Design Values for Wood Construction, revised prescriptive span tables and other updates to AWC’s standards and design tools. Also visit www.southernpine.com to obtain easy-to-use span tables for specific grades and sizes of Southern Pine lumber.
SPIB and Timber Products Inspection are currently working to complete the full In-Grade matrix by destructively testing Select Structural 2x4s, No.2 and Select Structural 2x8s, and No.2 and Select Structural 2x10s in bending, tension and compression. Additional design value changes are expected once all the testing is completed later this year. Moving forward, Southern Pine will continue to be monitored with annual destructive testing.
Southern Pine remains strong, dependable
“Southern Pine remains one of the best construction products on the market today,” said Cathy Kaake, senior director of engineered and framing markets for the Southern Forest Products Association (SFPA). “Southern Pine users have many available product options, including visually graded dimension lumber and an increasing supply of mechanically graded lumber,” added Cathy.
SFPA continues to provide answers to common questions, including impacts on real-world applications. One common question is, “Do new design values impact studs?” A short answer: “There is no change for studs based on the International Residential Code.” Southern Pine users can find answers to more than 30 questions and other helpful information by visiting www.southernpine.com.
SFPA does not test lumber or establish design values. SFPA’s primary function is to market lumber products and to help users understand Southern Pine grading rules and design values.