Furnace flue penetration

Is this just a cosmetic issue or something else (clearance to combustibles OK)?

This does not appear to be an approved fire-stop and if it is and has been cut or altered (bent-to-hell) it no longer serves it’s intended purpose.
I’d write it and let the flue experts dicker it out, and take responsibility.
If that bracket is screwed to the flue it’s wrong.
Is that moisture staining I see behind it? Imagine that!

Barry it’s a vaulted ceiling and I wasn’t sure whether the firestop had to be at the lower (ceiling) plane or whether it could be at the upper (roof sheathing) plane.

I’ll say living space side based on your photo and be proven wrong by others.
This may not be the first time I was wrong.

fire stop should be in the living space and well sealed to keep any flame from entering the attic space

Sealed? Yes.

Inside, outside? No matter.

Must be firestopped. Absolutely, wether inside or out.

please explain ‘fire stopped’.

Is there an attic cavity above this or is the flue going outside from here??

If the flue passes through each level of the home i.e. bsmt. floor structure, first floor ceiling to attic, should be fire stopped at each level. Best application is sheet metal. Should be a tight fit around the flue. The flue should be a double wall thickness (B-vent) which usually carries a 1" clearance from combustible materials. A single wall type flue (C-vent) usually carries a 6" minimum clearance from combustible materials. This installation will “slow down” the spread of fire to each level of the home. With the flue cavity opened to other levels, could be considered a “stack effect” if opened.


Joe Nichols
Master Inspector/Owner
The HomeBiz Inspection Team
Frederick County, MD

Peter, Sorry, the sheet metal “panning” would be considered the “fire stopping”.