ASTM C 1921 sets in place the proper guidelines for properly evaluating and comparing impact
testing of outside 90 degree corner systems on gypsum panels. However, it does not considers all
of the ramifications of corner impacts. As evaluated and presented before this subcommittee in
May, 2022, we found that not only does the corner's nose take the brunt of the impact, but energy
is also transferred through the flanges that extend onto the sides of the wallboard. If or when these
flanges become delaminated, the owner is looking at a different scope of repair. Adding a
consideration for this condition should be added to this standard.