Q: What should I do if I used a different manufacturer’s gypsum panel in a proprietary system?

A: Using a gypsum panel from a manufacturer other than the one specified in a proprietary or fire-rated system can have significant implications for code compliance, fire resistance performance, and warranty coverage. To address this situation appropriately, follow these steps:

1.    Begin by identifying the system’s designation, such as the GA File Number (from GA-600-2024 - Fire Resistance and Sound Control Design Manual, illustrated below), UL Designation, or the specific fire test number. This identification is critical to ensure you're referencing the correct tested construction and to facilitate accurate comparisons.

2.    Contact the Technical Departments: Reach out to the technical departments of each gypsum panel manufacturer involved. Each manufacturer should be able to provide documentation for their own fire-tested assemblies that closely match the referenced design. In many cases, they may also advise whether their product can be considered an equivalent for the intended use.

3.    Compare Design Assemblies: Evaluate the assemblies for key differences. Pay particular attention to factors such as:

o    Panel orientation

o    Fastener spacing

o    Joint alignment (in-line vs. offset)

o    Stud type and dimensions

o    Insulation requirements (if any)

The manufacturer’s technical staff can often assist with this comparison.

4.    Determine the Conservative Approach: Identify which assembly is more conservative and review the proposed solution with the Authority Having Jurisdiction (AHJ). Proceed with construction using the more conservative assembly, pending AHJ approval.

5.    Update Documentation: If changes are necessary, issue a change order to reflect the revised assembly in the construction documents.

6.    Obtain Documentation (if required): In some cases, the AHJ may require a letter from the gypsum panel manufacturer(s) confirming the acceptability of the substitution.

7.    Maintain Records: Regardless of whether a letter is required, it is essential to notify the manufacturers involved. Doing so ensures a record is maintained, which may be important for warranty validation or in case any issues arise in the future.

Have more technical questions? The GA’s Technical Services Department provides technical assistance for design, construction, and code enforcement professionals. Call 301-277-8681, email info@gypsum.org, or submit your question online.

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