The home inspector is looking at a damper plate in the exhaust flue above a wood burning fireplace with a gas log lighter pipe.
When the damper is open, it allows exhaust gases and smoke to draft up the flue… when closed, it stops cold air from coming down the flue.
The gas log has a gas control valve, typically installed outside of the fireplace in the wall.
If an older gas valve leaks or the valve is accidentally turned-on… natural gas will accumulate in the fireplace with the damper plate closed 100% – a big health safety concern.
Building requirements call for a $3 C-clamp to be installed on the edge of the damper plate to keep it slightly open in the event there’s gas flow in the fireplace.
Now if gas does leak into the fireplace, it will rise to the top of the chimney flue and not come into the household.
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