20/06/2026
If your chimney sweep has ever mentioned the mid-feathers in a chimney stack, this is what they're talking about.
Mid-feathers are the dividing walls between the flues inside a chimney. Their job is to keep smoke and harmful gases separated, preventing them from crossing from one flue to another.
They also play an important role when a chimney liner is installed. If the mid-feathers are damaged and not properly repaired, birds can gain access and nest in the void between the liner and the brickwork, leading to blockages and potential safety issues.
