SELKIRK CORP 208465 8-Inch Fire Stop Joist Shield 8", 8T-JS, Firestop Joist Shield Prevents or delays the rapid spread of fire, regardless of the cause, in a home or building Required to assure ample fire protection when the chimney passes through an intermediate floor An intermediate floor is one that does not include the location of the appliance nor an open attic A typical application where a firestop joist shield should be used is where the appliance is installed in the basement of a two-story house