Concerned over news reports of residential deck collapses, a task force headed by the American Wood Council (AWC) of the American Forest & Paper Association (AF&PA) has created a deck design guide to foster the construction of better engineered and built decks.

The guide, “DCA6: Prescriptive Residential Deck Design Guide,” was developed in conjunction with the International Code Council (ICC) and Fairfax County, Va.

Task force participants included NAHB, APA–The Engineered Wood Association, Simpson Strong-Tie, Southern Forest Product Association and the WTCA representing the structural building components industry. NAHB’s Construction Codes & Standards staff worked to make the guide as builder-friendly as possible.

Part of the AWC’s Design for Code Acceptance series, the guide provides details, span tables, guardrail requirements and other provisions for constructing a residential deck in accordance with the International Residential Code.

The guide also contains recommended good practices for deck construction that are not specifically code requirements.

AWC members requested the development of the guide, noting the lack of prescriptive code requirements in the IRC and of consistent, up-to-date guidance and details from other industry sources.

The guide incorporates the attachment table for deck ledgers developed by Frank Woeste at Virginia Tech University. Building officials approved the table for inclusion in the “2007 Supplement to the International Residential Code.”

The table specifies bolt or lag screw spacing for attaching deck ledgers either to a rim board or to a concrete or CMU wall. The table covers both solid sawn and engineered wood ledgers and rim boards.

ICC plans to market the guide to building officials as a deemed-to-comply option for constructing a residential deck. The intent is for building departments to offer the guide to builders and home owners in place of requiring a formal plan submission in order to obtain a deck permit.

The guide is limited to single-story decks and does not address wind and seismic loads, snow loads or unique loads such as hot tubs. Decks constructed per the guide may not be attached to cantilevered house framing or masonry veneers.

Deck designs and loads falling outside the scope of the guide will require a plan submission.

The guide does not supersede existing deck details offered by local jurisdictions, nor does it prohibit a builder from separately designing a deck using the IRC and applicable standards, or retaining a registered design professional.

Deck Design Guide Available Free From AWC

The “Prescriptive Residential Deck Design Guide” is available as a free download from the AWC Web site at www.awc.org

For more information, e-mail Gary Ehrlich at gehrlich@nahb.com, or call him at 800-368-5242 x8545.

This article is republished with permission from Nation’s Building News, the online weekly publication of NAHB.