Frequently Asked Questions
For structural composite lumber (SCL), should the volume factor, CV be applied to Fb* in calculation of the beam stability factor, CL or is it intended that CV be applied following calculation of CL?
Where CV > 1, it is intended to be applied to Fb* prior to calculation of the beam stability factor, CL. For SCL, application of CV > 1 to Fb* prior to calculation of CL is analogous to application of the size factor for lumber in determination of the appropriate Fb*. The increased value of Fb*, applicable for a fully-braced member, is the appropriate reference value for calculation of the ratio of critical buckling design value to fully-braced reference design value (FbE/Fb*) used to determine CL.
Wood Products
- Why are the wind speeds in Minimum Design Loads for Buildings and Other Structures, ASCE 7-10 so much higher than those in ASCE 7-05?
- Where can I find information on federal specifications and standards for lumber and wood products?
- What are the design manuals for wood construction in high wind areas?
- What resources are available for wood construction in high seismic areas and why build with wood in earthquake-prone areas?
NDS
- What is the difference between 2012 NDS 3.5 and 2012 IBC Table 1604.3 Footnote d for adjusting long-term deflection of wood members?
- What do the column headers for bolt design value tables 11 A-K in the NDS mean?
- Where can I find background on In-Grade Testing for the NDS supplement?
- Where can I find more information on all of the NDS references?
- What are the safety factors (factor of safety) that are used to derive allowable design values for wood fasteners, lumber design values, etc. referenced in the NDS?
- Why did shear parallel to grain (horizontal shear) design values increase in the 2001 NDS?
- If there's an existing structure where the MC<19% for southern pine timbers, could the designer back out the wet service adjustment from the NDS published design values in table 4D?
- For structural composite lumber (SCL), should the volume factor, CV, be applied to Fb* in calculation of the beam stability factor, CL, or is it intended that CV be applied following calculation of CL?
LRFD
- What is LRFD?
- What is the purpose of the NDS Format Conversion Factor, KF?
- For LRFD in the 2005 NDS®, why does the φ factor cancel out when adjusting nominal resistances using the LRFD Format Conversion Factor, KF , and the resistance factor, φ?
- For Load and Resistance Factor Designs (LRFD), many of the design examples and much of the discussion focuses on elastic stress analysis. I thought that one of the benefits of LRFD was its ability to accommodate plastic (non-linear) analysis. Why don't you cover plastic design considerations in your standards?
WFCM