More than two decades ago, abuse-resistant gypsum panels and impact-resistant gypsum panels were developed for application in high-traffic and heavy-wear areas. Often referred to as “AR” panels and “IR” panels, these products have denser cores and tougher, more resilient facers. AR/IR panels are heavier than traditional 5/8-inch type X gypsum wallboard by an average of at least 25 percent. The ratings or performance of the AR/IR panels—Levels 1 to 3—are defined by ASTM C1629 Standard Classification for Abuse-Resistant Non-Decorated Interior Gypsum Panel Products and Fiber-Reinforced Cement Panels. Hospitals, schools, college dormitories, gymnasiums, and minimum-security prisons are a few examples of places where these panels provide a high-performance alternative to other technologies.
At the time AR/IR panels were introduced—the 30-mil steel stud—commonly referred to as a 20-gauge drywall/curtainwall stud or simply a 20-gauge stud, was standard in non-load bearing steel stud framed walls. However, within the last 15 years, metal framing manufactures have introduced a family of studs with thinner steel of greater hardness, engineered to achieve the same height limitations/structural performance as 30-mil studs. Also known as “20-EQ” studs, these equivalent metal framing studs have a 19-mil designation. Subsequently, and to minimize confusion, the metal framing manufacturers moved away from using the term “gauge” and switched to “mil” thickness. 20-EQ studs vary in the marketplace from a measured thickness of 19 to 23 mils, so for simplicity we will refer to them as 20-EQ in this article.