With constant code changes and the scramble among manufacturers to make sure their products comply with the newer codes, there can be confusion in the specification community as to which products are approved for use in the field.

To help our customers better understand these issues, it's important to first review the product evaluation process and then discuss some of the specific product lines that have been affected by new code changes.

Product Evaluation Process

Products that are not specifically mentioned in building codes must have some mechanism for determining if the products comply with the code. For example, the International Building Code® (IBC) does not say "Use an HUS26 to support the ends of joists," but it does say "Connections depending on joist hangers or framing anchors, ties and other mechanical fastenings not otherwise covered are permitted where approved. The vertical load-bearing capacity, torsional moment capacity and deflection characteristics of joist hangers shall be determined in accordance with Section 1715.1."

So in order to approve the hanger, a code official would need to determine if it was tested and evaluated as required in Section 1715. There are two ways code officials can assess this; they can personally review the manufacturer's testing and calculations required by 1715.1, or they can rely on an evaluation report published by a product evaluation agency. Understandably, many code officials choose to rely on evaluation reports.

To achieve an evaluation report, a manufacturer must submit product information and testing to evaluation agencies like ICC-ES and IAPMO ES. These evaluation services evaluate the building products based on Acceptance Criteria. Products that meet the Acceptance Criteria receive an evaluation report, stating that the product either complies with the code or is an alternate to what is specified in the code. Engineers, specifiers and contractors may rely on these reports to determine whether to specify or purchase a particular product while code officials use them to verify approval.

As described above, in some cases the approval criteria for a product is spelled out in the code. For many other types of products though, the code and its referenced standards are not as specific as to how to evaluate a product. In these cases, IBC Section 104.11 states that "An alternative material, design, or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of the code."

If the code does not specify how a product is to be evaluated, then it's typically up to the evaluation agency, working in conjunction with manufacturers and interested parties, to develop a specification on how to evaluate a product, which is known as an Acceptance Criteria or an Evaluation Criteria. The challenges for evaluation agencies and manufacturers are first to develop separate evaluation criteria for each type of product and then to revise the criteria whenever the applicable building code changes or when other changes are merited.

Developing the Acceptance Criteria and then providing documentation in accordance with new requirements is a time intensive process and helps explain why some products may have evaluation reports for older codes, but not for newer ones. In many cases, it's not that the product does not comply with the newer code, but more likely that the Acceptance Criteria for the newer code has not been developed; the manufacturer is in the process of submitting their updated product information to the evaluation agency; or the agency has not yet completed their review of the submitted information.

Two Simpson Strong-Tie® product lines without specific evaluation criteria in the IBC, include Steel Strong-Wall® prefabricated shearwalls and Simpson Strong-Tie Anchor Systems® post-installed adhesive anchors for concrete. Changes in the IBC and in ICC-ES Acceptance Criteria have affected the evaluation reports for these products and therefore should be discussed in more detail.

Anchors In Concrete

Our anchor systems products have been affected by changes to referenced standards in the IBC. The 2000 IBC contained new provisions for the strength design of cast-in-place concrete anchors that became part of ACI 318-02 Appendix D. Once ACI 318-02 was completed, it was referenced in the 2003 IBC for the design of concrete. For the first time, that standard contained a mandatory Appendix D that outlined design requirements for both cast-in-place anchors (e.g. headed studs, headed bolts, J-bolts and L-bolts), and post-installed expansion and undercut anchors (excluding adhesive anchors, powder actuated fasteners and specialty inserts). While these new requirements were significantly different and more rigorous than design and analysis methods that had been used in the past, they also significantly reduced the strength of concrete anchors compared with previous methodologies.

Along with ACI 318-02 Appendix D, the American Concrete Institute also published a new test standard, ACI 355.2-01, Evaluating the Performance of Post Installed Mechanical Anchors in Concrete. This test standard became the basis for the new ICC-ES Acceptance Criteria AC193 for Mechanical Anchors in Concrete. In addition to AC193, ICC-ES adopted a new Acceptance Criteria AC308 for Post-Installed Adhesive Anchors in Concrete. These new Acceptance Criteria take into consideration the new provisions of Appendix D. Since these new criteria covered strength design and concrete only, the old ICC-ES Acceptance Criteria for adhesive anchors and mechanical anchors (AC58 and AC01, respectively) were revised so that they applied only to masonry elements.

Once the new Acceptance Criteria were published, ICC-ES revised manufacturers' existing evaluation reports to remove recognition for post-installed anchors in concrete. New evaluation reports for post-installed anchors in concrete require extensive testing efforts using the new Acceptance Criteria. For example, tests now have to be performed in cracked and uncracked concrete, in cleaned and partially cleaned holes, and in dry and water saturated holes. Furthermore, anchors have to be creep tested at two temperatures, tested in cracked concrete where the crack width is cycled and tested in cracked concrete under a simulated seismic test. This is in addition to the many embedment depths, spacing and edge distances, and load directions that must be tested for each anchor size.

Simpson Strong-Tie is in the process of completing this laborious effort. Currently, our Strong-Bolt® anchor and Titen HD® anchor both carry a 2006 I-Code evaluation report for concrete that is in compliance with AC193. Our new self-undercutting Torq-Cut™ anchor is under review for 2006 I-Code and AC193 compliance with an evaluation report expected in early 2009. Our new adhesive anchor product, SET-XP™ Epoxy-Tie® Adhesive, carries a 2006 I-Code evaluation report for uncracked concrete that is in compliance with AC308 and is expected to be reissued for cracked concrete recognition in January 2009. The new IXP™ Adhesive Anchor Insert, to be used with SET-XP™ Epoxy-Tie® Adhesive, has been tested in accordance with AC308 and is expected to have an ICC-ES evaluation report early in 2009. Check www.simpsonanchors.com for the latest information about our anchor product line.

Prefabricated Shearwalls

Our Steel Strong-Wall® products also have been affected by the Acceptance Criteria process. When first introduced, ICC-ES did not have an Acceptance Criteria for steel prefabricated shearwall panels. In its current ICC-ES evaluation report (ESR-1679), this product was evaluated under the 1997 Uniform Building Code® and the 2000 and 2003 I-Codes.

Over the past few years, ICC-ES along with industry (Simpson Strong-Tie, other manufacturers, design engineers, academia, associations, etc.) have developed new Acceptance Criteria for this type of product, which resulted in the publishing of AC322 in October of 2007 - Acceptance Criteria For Prefabricated, Cold- Formed, Steel Lateral-Force-Resisting Vertical Assemblies. Part of the criteria contained in the new AC322 for steel panels was carried into the existing requirements for wood shear panels, AC130. Working under the new AC322 and the revised AC130, which took effect March 1, 2008 and November 1, 2007 respectively, Simpson Strong-Tie is currently completing the testing and analysis required to obtain an evaluation report for these products for the 2006 IBC and IRC. In the meantime, many building departments have developed interim guidelines for acceptance of prefabricated shearwall panels until 2006 IBC/IRC evaluation reports can be obtained. Check with your local code official for their policy.

One other important item regarding ICC-ES Evaluation Reports is the creation of a new report for Simpson Strong-Tie connectors, ESR-2523. This is what's called an "Index Report." It does not contain any technical information, but instead lists every stamped (automated) and welded connector that has an ICC-ES evaluation report and the respective report number. Connectors included in ICC-ES Evaluation Reports will be identified by a label or stamp containing this number, which provides an easy-to-use method for building inspectors to verify approval.

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Reprinted from the Structural Report, Volume 5, Number 3, July 2008. Subscribe to the Structural Report, our free quarterly newsletter.