When is Engineering Required? City of Atlanta Issues New Code Interpretation


By: Cheryl H. Shaw
The City of Atlanta recently published its second International Residential Code interpretation of 2017, confirming that structural designs utilizing Structural Composite Lumber (SCL) must be designed and sealed by an engineer licensed to practice within the State of Georgia. The stated purpose of the binding interpretation is to provide consistency between the Office of Building staff and design professionals who issue construction documents in multiple jurisdictions.
In issuing the interpretation, the City noted the IRC’s requirement that structural elements which do not conform to the prescriptive requirements of the code must be “designed in accordance with accepted engineering practice.” To this end, while visually-graded lumber is regulated by span tables within the code, SCL, a proprietary engineered wood product, does not have span tables or design values represented within the IRC. Instead, design values are furnished by manufacturers. Although manufacturers have created design software that is widely available, the only party authorized to provide an “engineered design” for structural elements is an engineer.
Accordingly, all residential construction documents submitted for permit that utilize SCL must be designed and sealed by a licensed Georgia professional engineer. In addition to identifying the type, size and manufacturer of the SLC, the engineer must provide other design-specific information.  A link to the interpretation with a complete list of requirements can be found here: 2007-IRC-002. The requirements apply to Laminated Veneer Lumber (LVL), Parallel Strand Lumber (PSL), Laminated Strand Lumber (LSL), and Oriented Strand Lumber (OSL).
Unnecessary engineering can increase construction costs, but failing to obtain required engineering can result in costly delays. Understanding when engineering is required—and when it is not—is critical to the success of your project. FMG’s Construction Law practice group is here to help. If you have questions or would like more information, please contact Cheryl H. Shaw at [email protected].