The condition of your Chimney Stack is vitally important. Chimneys are obviously exposed to the elements and receive the full force of any adverse weather such as rain, snow and frost. They are also exposed to intense heating and cooling (if the flues are in use) condensation and chemical reactions from hot flue gases. All of these factors can potentially lead to the failure of the Stack or the collapse of the mid feather walls (dividing walls between multiple flue ways) a collapsed mid feather wall will block the flue rendering it unusable.
In older properties the Internal Flue system of the Chimney would have been built in brick,stone or cob and lime mortar, this would then be parged with a lime/mortar render in order to line the flue system to protect the Brickwork, Stone or Cob and to prevent gases escaping through mortar joints, Over time this will deteriorate causing the ‘Parging’ to fail and fall off, this can not only cause blockages in the flue it can potentially allow poisonous gases to escape into living areas… this may cause staining on walls or a smell of smoke in upstairs rooms and loft spaces.
IF YOU SUSPECT THAT YOU HAVE A BLOCKAGE IN YOUR CHIMNEY DO NOT USE UNTIL THE CHIMNEY HAS BEEN INSPECTED.
Most Chimney pots are made from terracotta which can be prone to cracking during extreme changes of temperature (Chimney Fire being the main reason for a cracked Chimney Pot). The Chimney Pot sits on top of the brickwork and is kept in place by a bedding of mortar known as ‘flaunching’. This also provides weather proofing to the Chimney Stack, preventing water penetration. In older properties the flaunching is usually lime mortar and can deteriorated over the years. The pots themselves may still be sound but they are often not secure as the flaunching may have cracked and fallen away. In extreme cases insecure chimney pots could topple in high winds resulting in damage to property or injuries to passers by. It is, therefore, extremely important that the condition of chimney pots and flaunching is checked on a regular basis.
When repair or restoration is required this work should be carried out by an experienced bricklayer as it is important that the right materials and techniques are used.