Selkirk 206465 Firestop Joist Shield, 6", #6T-JSRequired to assure ample fire protection when the chimney passes through an intermediate floor, an intermediate floor is 1 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 2 story house, as an example with the appliance installed in the basement, firestop joist shield should be installed between the first &