A Complete Residential Concrete Code
The first edition of the ACI 332 Code – Requirements for Residential Concrete Construction, has been published. Chapter 7 (Foundation Walls) is referenced in the 2006 Edition of the International Residential Code. But what comes next? The 332 Committee has begun working on the next version (’07) with a goal to make it a complete residential concrete code. It should be noted that this effort has the enthusiastic support of ACI.
Many compromises (i.e. deletions) were made in producing the inaugural version, ACI 332-04, in order to get the approval of ACI’s TAC (Technical Activities Committee) engineering staff, agreement of committee members, and to meet the deadline for inclusion in the 2006 IRC. The cycle starts anew as the committee begins work on the 332-07 version of the Residential Standard (Note: the document is a standard until adoption by a legal jurisdiction, at which time it becomes a code). The goals of the committee are inclusion of the provisions that were deleted during the development of the ’04 version of the Standard, and reference of the entire Standard in the 2009 version of the IRC. The 332 Standard must be published nearly 2 years ahead of the code in order for it to be considered.
Incorporation of a design section for foundation walls and footings is a primary goal for 2007. The design section will include plain structural concrete (no vertical steel), moderately reinforced concrete (less than minimum ACI 318 required steel but sufficient to carry the loads), and a full design section with the modified design parameters included in the ’04 version. The benefit of the inclusion of a moderately reinforced section will be a reduction in the amount of vertical steel currently required in the empirical tables of the 332-04 version once the maximum loading conditions for plain structural concrete have been exceeded. The design provisions were in one of the earlier drafts of 332-04 but were deleted at the request of ACI. ACI-318 will no longer be referenced for residential foundation applications.
Inclusion of provisions for seismic design will make the document applicable to all regions of the US residential construction market. The primary impact of this will be load calculations, connections and design provisions for structures in Seismic Zones D, E, and F. Most CFA members will not be impacted by this change.
Finally, the inclusion of empirical design criteria for above grade residential concrete wall systems will be added. This is a very important step for continued growth of this market. Provisions for above-grade design of concrete systems are already in the IRC because of previous efforts of the PCA and ICF industries. However, the new provisions will reference all forms of above-grade walls regardless of the forming system used.
The 332-07 document with all new items must be developed, approved, balloted, and published within the next 18 months in order to be considered for the 2009 IRC. Once this edition is completed, the only exclusions will be cantilevered retaining walls and structural concrete decks and slabs. They will be on the agenda for the 2010 version of the 332 Standard. That doesn’t mean slabs and retaining walls can’t be constructed – but they will need to be designed in accordance with ACI 318, the current design method for these building elements.
A residential code, separate from the commercial code (ACI-318) has been a priority of the CFA for at least the past 10 years and it is great to see some progress toward this goal. I would like to welcome Kirby Justesen to the 332 Committee. He joins Buck Bartley, Barry Herbert, Brent Anderson, Jim Baty and myself to make certain the interests of the contractors who build these structures are represented. The 332 Committee has created sub-committees for each of the major residential concrete components (slabs, foundation walls, footings, above grade walls, materials, etc.) which provides opportunities for participation from a much broader cross-section of the industry. If you have an interest in working on this important document, contact Jim Baty, ACI 332 Secretary and CFA Technical Director at 866-232-9255 or jbaty@cfawalls.org.
Ed Sauter, Executive Director, CFA esauter@cfawalls.org