The purpose of this note is to share some lumber design information and ask for your help with our next Virginia Tech short course program. If you haven’t already read about it, the agencies that write rules for lumber grading and publish allowable design stresses are currently evaluating allowable stresses for their products. For example, effective June 1, 2012, SPIB has updated the allowable properties of 4x4 (and smaller) No. 2 Dense and lower grades of Southern Pine (SP) and Mixed Southern Pine:
http://www.spib.org/pdfs/Supplement-No-9-Tables-2002-sml-2x4-only.pdf
So far, the only dimension lumber products that have been affected are visually stress rated (VSR). For example, MEL and MSR 2x4 grades of Southern Pine are not affected by the June 1, 2012 SPIB update. This outcome may be surprising in that a tree doesn’t know how it may be graded for lumber. To help understand why SP MEL and MSR lumber were not affected by the June 1, 2012 update, the following link gives an explanation of how the grading methods differ and why only the VSR 2x4 No. 2 Dense and lower grades were affected:
http://nfba.org/uploads/Effect_of_Variability_on_Lumber_Design_Values.pdf
Regarding our next VT short course:
Introduction to Structural Design of Wood Buildings per the 2012 NDS
October 10-12, 2012, Virginia Tech, Blacksburg, VA
For details, please visit www.cpe.vt.edu/sdww/.
Our e-mail contacts are limited to the folks that have already participated in a Virginia Tech short course. It would be extremely helpful to our next program if you would forward this e-mail to someone that you believe may not be aware of our educational programs.
Thank you, Frank
Frank Woeste, P.E.
Professor Emeritus
www.cmec.wsu.edu/facultypages/WoesteResume.pdf
http://www.spib.org/pdfs/Supplement-No-9-Tables-2002-sml-2x4-only.pdf
So far, the only dimension lumber products that have been affected are visually stress rated (VSR). For example, MEL and MSR 2x4 grades of Southern Pine are not affected by the June 1, 2012 SPIB update. This outcome may be surprising in that a tree doesn’t know how it may be graded for lumber. To help understand why SP MEL and MSR lumber were not affected by the June 1, 2012 update, the following link gives an explanation of how the grading methods differ and why only the VSR 2x4 No. 2 Dense and lower grades were affected:
http://nfba.org/uploads/Effect_of_Variability_on_Lumber_Design_Values.pdf
Regarding our next VT short course:
Introduction to Structural Design of Wood Buildings per the 2012 NDS
October 10-12, 2012, Virginia Tech, Blacksburg, VA
For details, please visit www.cpe.vt.edu/sdww/.
Our e-mail contacts are limited to the folks that have already participated in a Virginia Tech short course. It would be extremely helpful to our next program if you would forward this e-mail to someone that you believe may not be aware of our educational programs.
Thank you, Frank
Frank Woeste, P.E.
Professor Emeritus
www.cmec.wsu.edu/facultypages/WoesteResume.pdf
