To slow or prevent the spread of fire, building codes require fire-resistant or fire-rated assemblies in certain locations, occupancies, and types of buildings. When fire-rated walls and/or floor/ceiling assemblies are required, a fire barrier over the walls is typically necessary to prevent flames from escaping the confinement provided by the wall or ceiling assembly. The barrier may be in the form of continuous rim board on top of the wall and parallel with the floor joists or as continuous rim board along the top of the wall and perpendicular to the joists.