What is a soot door?

A soot door, also called a chimney cleaning door or flue access door, is a small sealable door in a chimney or flue where soot collects during sweeping. After the sweep, the door is opened to remove the soot and inspect the flue. In Dutch it is called a ‘veegluik’ or ‘roetluik’. On stainless steel flue systems, the same job is usually done by an inspection tee with a removable cap.

Application

• Masonry chimneys: in older houses the soot door often sits at the base of the flue, behind the stove or in an external wall.
• Metal flue systems: an inspection tee or access section in a single or twin-wall stainless steel flue.
• Ventilation ducts: mechanical and balanced ventilation systems have access panels too. They are not for soot but for removing dust and dirt from the ducts.

A soot door in an external wall has practical benefits: no soot in the living room, no need to move the stove, and the sweep can work without anyone being home.

Materials

Soot doors are made of cast iron, steel, stainless steel or concrete, sometimes with a fitted frame. Choose one rated for the flue temperature and with a tight seal.

Sweeping

HETAS, the UK body for solid fuel and biomass heating, advises sweeping a chimney at least twice a year when burning wood and at least once a year for smokeless fuels, and more often with frequent use. In the Netherlands, the Dutch insurers’ association advises at least once a year. Keep the sweep’s certificate, as insurers may ask for proof of maintenance after a chimney fire.

Tips and points of attention

• Leaking door: a poorly sealing soot door leaves soot marks on the wall and lets in false air, which weakens the draught. Check the seal after every sweep.
• Offsets: where a flue bends, an access door near the bend makes proper cleaning much easier.
• Keep it accessible: do not box it in behind panelling or a cupboard.
• Use a qualified sweep: a lined flue still needs regular sweeping.

Related terms

• Chimney
• Chimney flue pipe
• Open fireplace
• Mechanical ventilation
• Balanced ventilation

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