Span Tables Published Based on SPIB's Proposed Design Values

Originally published by: Southern Forest Products AssociationNovember 11, 2011

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The Southern Forest Products Association (SFPA) has posted on its website the maximum span capabilities for Southern Pine joists and rafters, using the Southern Pine Inspection Bureau’s (SPIB) proposed design values for visually graded dimension lumber. The seven tables list spans for the most common loading conditions.  Also available on the site is a series of bar graphs comparing Southern Pine spans – for No.1 and No.2, 2x6 through 2x12 – with hem fir and spruce-pine-fir. Links to this information now appear on the site’s landing page for New Design Values.

Last week, SFPA posted on its site a summary table listing new design values for visually graded dimension lumber, based on SPIB’s submittal to the American Lumber Standard Committee (ALSC) Board of Review.  All information is pending ALSC’s approval. Prior to ALSC’s  next meeting – set for January 5, 2012 in Washington, DC – ALSC is soliciting written comments from all interested parties, to be received at least 10 days prior to the meeting. Direct comments to Tom Searles, ALSC President by fax to 301/540-8004, or by e-mail to

“As a service to all segments of the lumber industry, SFPA is providing this maximum span table data and comparisons with other species to all levels of the Southern Pine lumber manufacturing and supply chain,” said SFPA President Adrian Blocker. “The impacts that proposed design values from SPIB will have on Southern Pine span capabilities have been one of the most-often asked questions.  SFPA is here to serve our members’ customers and help the dialog progress to a better understanding of the design value development process and the resulting data,” he added. 

Also from SFPA’s new SPIB Proposed Design Values page, visitors can review news releases with comprehensive background information, plus a collection of updated answers to 30 most frequently asked questions.  A link is provided to the current design values that remain effective until SPIB publishes new design values in its Supplement No.9 to the 2002 Standard Grading Rules for Southern Pine Lumber sometime next year.

The last major change for visually graded dimension lumber occurred in 1991 when design values for Southern Pine and other North American species were published based on In-Grade testing of full-size samples of commercially produced lumber. Since 1994, SPIB has conducted an annual resource monitoring program developed in collaboration with the U.S. Forest Products Laboratory (FPL). SPIB is the first rules-writing agency to submit new values. Rules-writing agencies responsible for other species are in different stages for evaluating design values.

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.

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