Fire blocking
Fire blocking or firestopping is a system of supplemental components in a wood-framed wall or ceiling, which prevents the rapid propagation of fire within a combustible framing cavity to other areas. == Description and function == In wood-framed construction, fire blocking usually takes the form of short lengths of the same dimensional lumber used in the wall or floor/ceiling framing, installed perpendicular to the primary structural framing, completely obstructing the wall cavity.