Frequently Asked Questions
Where can I find information on wood shrinkage?
Here are some resources for this issue:
1. General information is available in the Structural Lumber Supplement of the AF&PA ASD Manual http://www.awc.org/Standards/nds.html. The longitudinal direction shrinkage (from green to oven dry) for normal wood usually ranges from 0.1 to 0.2 percent of the green dimension. For the radial and tangential directions, there is an approximate 1% change in dimensions per 4% change in moisture content.
2. USDA Wood Handbook Chapter 4.
http://www.fpl.fs.fed.us
3. WWPA Shrinkage Tech Note: http://www.wwpa.org/_techguide/shrinkage.asp
4. Canadian Wood Council's "DimensionCalc" will calculate for the dimensional change in wood due to shrinkage. The calculator is available at: http://www.cwc.ca/Resources/E-Tools/?Language=EN
Wood Structural Issues
- Are there deflection limits for cantilevers?
- Where can I obtain information on construction tolerances?
- Where can I find information on wall bracing requirements at corners with openings?
- What is creep and how can I address it?
- How do I calculate a capacity for lumber sheathing or heavy timber decking diaphragms?
- What is the load duration factor (CD)?
- How do I design for notches in a bending member?
- Are there design values for shear perpendicular to grain?
- Are there span tables for cantilever beams?
- Where can I find criteria for vibration control for wood members?
- Where can I find information on designing wood frame structures for performance?
- Where can I find information on wood shrinkage?
- Is there a design method for increased buckling capacity of built-up wood beams?
- Does gypsum provide lateral support for wall studs?
- Per the 2005 NDS®, which Emin should be used for the design of an unbraced structural glued laminated timber column under purely axial load?
- NDS (2001/2005) Section 5.3.7 describes a specific loading scenario of "loaded parallel to the wide face of laminations" for application of the flat use factor, Cfu, for structural glued laminated timber. Does the flat use factor apply where eccentric column load induces moment in the y-y direction?