nails spec'ed in pennys

in the age of nail guns

Building codes specify what kind of nail, how many and where they are to be placed to fasten one piece of building material to another. In the United States, the kind of nail was usually described in pennys, for example, a 16d common nail.

nail gun photo

Now, however, most nails are driven with nail guns, not hammers. The nail guns use collated fasteners that are usually not traditional common nails. Collated nails often differ from similar common nails in diameter, length, coating and style of head. All these factors affect the strength of the nailed joint. To achieve an equally strong joint with the new nails may require changing, for example, the number of nails and their spacing. Contractors and building inspectors are left in a quandary.

This issue has been addressed by the International Code Council, the people behind the International Building Code. Authoritative guidance on nail substitution can be found in the following publications (all require the free program Adobe Reader.)

ICC Evaluation Service, Inc.
Legacy report on the 2000 International Building Code®, the 2000 International Residential Code®, the 1998 International One and Two Family Dwelling Code®, the 2002 Accumulative Supplement to the International Codes™, the 1999 Standard Building Code®, the BOCA® National Building Code/1999, and the 1997 Uniform Building Code™.
Revision A, August 1, 2004.

On the web at

See also

Technical Topics: Minimum Nail Penetration for Wood Structural Panel Connections Subject to Lateral Load (TT-045B, Oct. 2007)

From APA, the engineered wood association. Deals with the necessary lengths of 8d and 10d nails.

The trade association of nail manufacturers provides useful articles on the relationship between ICC reports and the local code authority: Release No, The Fastener Isn't Code Approved.htm

Some manufacturers of nail guns provide code compliance information on their web sites, for example, 

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