By Corey Nigh
One of the earliest test standards for building construction systems is ASTM E72. This standard defines how to test building panels in several applications, and the results can be used to determine if a building panel is code compliant. Due to advances in technology and building science that have changed the way this standard is used, a committee made up of product manufacturers, engineers, test labs and other third parties have revised, updated and approved new versions of the standard. Because these revisions change how racking testing is performed, it’s important to keep abreast of the updates over the last several years.
One of the more recent revisions began in 2013, when an additional dial gauge was added to measure the compression in shear walls. The compression is subtracted from the system to determine net deflection, which results in a lower, more accurate net deflection during testing. This matches a common modification of the standard already used in many evaluation schemes.
Additionally, the acceptable range for moisture content of lumber was revised. Previously, it was required to be in the 12-15% range, but as this was found unnecessarily restrictive, the range has been extended to 6-15%. This revision allows product manufacturers more options so that test labs can complete their tests faster.
Additional changes in the 2014 version of ASTM E72 refine racking test procedures, to ensure more suitable results. One important change is that the rate of loading is no longer set at a fixed rate. Now, the load can be changed to best suit each building panel product, and the outcome is a test result that is accurate for a specific product and its intended use.
As innovation continues in the construction industry, building panel manufacturers continue to build new, exciting products that perform in unique ways - it’s only natural that test standards must also improve over time to continue providing reliable, repeatable information. The recent revisions to the racking test procedures are an improvement that offer a few more options for innovative products.
NTA is always up to date on the latest code and standard changes, and our nationally accredited lab is a leader in panel testing. Our testing and certification programs have always been adaptable to your needs, so contact an NTA account manager for more information on ASTM E72 testing today!