Edited sentence: Drywall panels are available in 4 ft (1219 mm) wide sheets of various lengths.For soundproofing or fire resistance, two layers of drywall are sometimes laid at right angles to each other.In North America, five-eighths-inch-thick drywall with a one-hour fire-resistance rating is often used where fire resistance is desired.In some commercial applications, sheets up to  are used.Larger sheets make for faster installation, since they reduce the number of joints that must be finished.Newly formed sheets are cut from a belt, the result of a continuous manufacturing process