Rationale

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.