More and more homeowners are enjoying log cabin homes as a quaint throwback to pioneer days combined with the comforts of modern day living. As such, an increasing number of log cabin-style homes and structures, including many in our national parks, have become much more elaborate than those in which Abe Lincoln and his contemporaries grew up.
The International Code Council Board of Directors observed this trend more than a decade ago and in 2003 began the process to make sure these log homes and other log structures were just as safe as those built of brick and mortar. The Code Council gathered experts from all fields to form the ICC Consensus Committee on Log Structures (IS-LOG), which operated under ICC’s ANSI-accredited standards development process. After much deliberation, the IS-LOG Committee developed ICC 400-2007: Standard on the Design and Construction of Log Structures, the first of its kind in the world to address the design and construction of log homes and other log structures.
In April 2010, the Code Council issued a call for volunteers for another Consensus Committee on Log Structures to improve upon what had already been accomplished. The committee was composed of: Rob Pickett, committee chair, representing the Log Homes Council, NAHB, Rob Pickett and Associates, Hartland, Vermont; David Icove, P.E., vice chair, research professor, University of Tennessee, and of the Min H. Kao Department of Electrical Engineering and Computer Science, Knoxville, Tennessee; Larry Beineke of the PFS Corporation, Raleigh, North Carolina; Thomas Castle of Ficcadenti Waggoner & Castle, Walnut Creek, California; Christopher Clay of Great Lakes Log Crafters Association, Knife River, Minnesota; Gary Hautman of the Douglas County Building Division, Castle Rock, Colorado; James “Jay” Horner of the City of Gatlinburg, Gatlinburg, Tennessee; Robert G. Kenel of the Great Lakes Log Crafters Association, president, R.G. Kenel Log Builders LLC, St. Charles, Michigan; Sharon Walter of the City of Highland, Highland, Illinois; and Bob Warren, president of the BC Log and Timber Building Industry Association, Khita Log Builders Ltd., Rossland, British Columbia. Ed Wirtshoreck, Manager of Standards for the Code Council, served as the staff secretariat.
By December 2010, the new Consensus Committee had a first draft ready for public review and comment. In March 2011, a second draft was prepared, and in August 2011, ICC 400-2012 received final approval by ANSI as an American National Standard.
Significant changes between the 2007 and 2012 editions of ICC 400 include:
• Updated allowable species combinations for hardwood and softwood logs
• Updated allowable design values for sawn and unsawn round timber beams
• Updated base design values for wall logs
• New prescriptive provisions for roof overhangs
• New prescriptive provisions for electrical wires in log walls
• Updated thermal values (U-values) for log walls
• New insulation and fenestration requirements (R- and U-value) for building components
• New log wall infiltration requirements
Work on the next edition of ICC 400 is scheduled to begin in 2015 that will result in the 2017 edition, which is scheduled for reference in the 2018 International Codes.