Additional new design values submitted by the Southern Pine Inspection Bureau (SPIB) for Southern Pine lumber have recently been approved by the American Lumber Standard Committee (ALSC).
The newest design values to be approved are for No. 2 2×4 dense and n on-dense grades of Southern Pine. The size category includes material that is between two and four inches thick and two to four inches wide. Just as the previous SPIB rules these design values apply only to Southern Pine lumber, not to mixed Southern Pine.
Earlier this year, the ALSC approved new design values for No.2 and all lower grades of 2×4 visually graded Southern Pine dimension lumber. The new design values will become effective on June 1, 2012. Design values for all other grades and sizes of visually graded Southern Pine currently remain the same, pending results of testing scheduled for completion later this year.
All the new values can be found in Supplement No. 9 to SPIB’s 2002 Standard Grading Rules for Southern Pine Lumber, available online at www.southernpine.com.
A major change for visually graded dimension lumber last 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.
