The terms “cavity barrier” and “firestop” are often used interchangeably. While both are passive fire protection methods, there are a few key differences. As mentioned, a cavity barrier is a piece of fire-resistant material placed in enclosed, typically unused spaces within buildings. They are designed to prevent the spread of fire and hot gasses.\
In comparison, while firestops are also used to prevent the spread of flames and smoke, they typically come in the form of putty or intumescent clamps and are used to seal joints or gaps between pipes, conduits, or sockets and the walls through which they pass. It can also be used around fire doors, windows, and ceiling voids. That helps to maintain the fireproofing of a wall or floor by closing small yet still problematic gaps. In short, firestops seal any imperfections between building elements that should be fire-resistant.