When a steel-lined chimney is present the installer should have provided a fire proof flange to maintain a safe distance from combustible materials. This is often referred to as an attic insulation shield. The polyethylene installed on the ceiling can be installed to the outside edge of this flange, and sealed using acoustical sealant and tape.

At this time the junction between the flange and pipe should be inspected to see that it has been sealed with a sealant capable of withstanding high temperatures. If this has not been done, the client should be made aware.