Analysis of Inter-laboratory Testing of Non-loadbearing Gypsum/Steel-Stud Wall Assemblies

Published

December 1, 2007

Author(s)

William L. Grosshandler, Samuel L. Manzello, Alexander Maranghides, T Mizukami

Abstract

This report summarizes the results of a test program conducted in 2006 and 2007 by the North American Fire Testing Laboratories (NAFTL) consortium. Gypsum/steel-stud wall assemblies, nominally rated at 1-h, were tested by six different organizations in North America employing ten different furnace facilities following the guidance provided in ASTM E 119-00. The participating NAFTL laboratories arrived at an identical 1-h rating for the gypsum wall specimen tested according to their respective standard operating protocols. The average time to failure (defined by the temperatures reached on the unexposed side of the specimen) was 65 - 2.8 minutes. The variability in individual peak thermocouple temperatures measured at similar locations on the different wall assemblies exceeded - 50DGF around one hour into the test, and reached a maximum of close to - 150DGF at the average time of failure. Differences in the time to failure for the ten close-to-identical wall assembly tests did not correlate at a statistically significant level with differences in average furnace temperature, the temperature-time integral, changes in ambient temperatures, or standard deviation among the furnace control thermocouple temperatures. Six inter-laboratory tests were also conducted by several Japanese organizations, yielding an average time to failure of 67.1 - 1.1 minutes. The inter-laboratory program described in this report is the largest ever conducted for fire resistance testing and forms the basis for future programs aimed at testing addential structural materials, elements and systems subjected to fire test standards referenced in building codes.

Citation

NIST Interagency/Internal Report (NISTIR) - 7471

Report Number

7471

NIST Pub Series

NIST Interagency/Internal Report (NISTIR)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.IR.7471

Keywords

gypsum, walls, wall assemblies, fire tests, steels, furnaces, ASTM E 119, standards, failure, thermocouples, gypsum board, specific heat, temperature, fire resistance rating

Citation

Grosshandler, W. , Manzello, S. , Maranghides, A. and Mizukami, T. (2007), Analysis of Inter-laboratory Testing of Non-loadbearing Gypsum/Steel-Stud Wall Assemblies, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.7471 (Accessed October 20, 2025)