It has never been swept

What has probably happened

• Burning wood always deposits creosote — the question is only how fast.
• Unseasoned or wet wood makes far more of it, because the fire runs cooler.
• Slow, smouldering, damped-down fires make more than hot bright ones.
• An oversized flue keeps smoke cool on the way up, so more condenses on the walls.
• Years of use without a sweep let it build into a hard glazed layer.

What the technician does

• The flue is swept from top to bottom and the debris removed rather than dropped into the room.
• A camera inspection of the full flue, so you see what is actually up there.
• The liner checked for cracks, gaps and missing mortar joints.
• Damper, smoke shelf and firebox cleaned and checked.
• Cap and crown inspected while the technician is on the roof.
• You are told plainly whether it is safe to burn, and what needs doing first.

Questions people ask

How often should it be swept?

The usual guidance is an inspection every year and sweeping whenever there is meaningful buildup. How often you burn, and what you burn, decides how often that is.

We only use it a few times a winter.

Occasional use still deposits creosote, and an unused chimney collects its own problems — nests, water damage, a rusted damper. The annual look is about the whole structure, not just soot.

It is a gas fireplace. Does that need sweeping?

It does not build creosote, but it still needs inspecting. Gas appliances vent carbon monoxide, and a blocked or deteriorating flue is dangerous in a different way.

How messy is it?

It should not be messy at all. A proper sweep seals the opening and works under vacuum. If someone is making a mess of your room, they are doing it wrong.