Frequently Asked Questions
What are the design manuals for wood construction in high wind areas?
The following design standards for wood construction in high wind areas are presently referenced in model building codes such as the IBC (International Building Code) and IRC (International Residential Code):
1. ANSI/AF&PA Wood Frame Construction Manual (WFCM) 2001 Edition
2. ICC Standard for Residential Construction in High Wind Regions (ICC-600)
The WFCM is an ANSI approved document that provides engineered and prescriptive requirements for wood frame construction based on dead, live, snow, seismic and wind loads derived from the 2000 International Building Code (IBC).
ICC-600 presents prescriptive methods to provide wind resistant designs and construction details for residential buildings. The standard is an update to SSTD 10-99 and includes new provisions such as prescriptive designs for wind speeds up to 150 mph with three-second gusts and exterior wall coverings for high wind.
Wood Products
- 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 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?
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