Chimneys may look rusty and murky to many but needs cleaning on a yearly basis. Although modern day chimneys are far more advanced than their old counterparts and have multiple levels of linings and protections to prevent fires however over time these safety measure tend to get worn out and have to replenished in order to ensure the safety of family members.
In old days chimneys were made of stone or bricks and had to be cleaned multiple times a year. But nowadays much emphasis is given by builders in making chimneys much more safe and durable. This is primarily because of the health hazards that are associated with them. So during chimney cleaning, whether it is done by professional chimney sweep or by an individual himself certain points have to kept in mind and some features have to be thoroughly checked before declaring that the chimney is clean.
Flues: Flues are the internal lining that is applied on top of the brickwork to provide an additional measure of safety. These not only prevent the bricks from deteriorating but also ensures that other parts of the house are not affected when the fireplace is working. Essentially they help to suck the heat from the fire. Since the flue is the first level of protection, hence they tend to be most affected by dust and soot.
2 Caps and Crowns: Chimney caps and crowns are generally placed to protect the exposed parts of the chimney which cannot be covered by flue lining. Although these are made from tough materials but over time small cracks might develop in them, which if left untreated can lead to major security concerns. Moreover, these parts are a common nesting place for animals as they provide natural shelter from the heat and cold. So during sweeps these caps and crowns should be properly patched and animal nests should be removed in order to facilitate their smooth performance.
3 Bricks: If a chimney is not cleaned in many years then the dust particles tend to eat away the internal lining of flues and can directly affect the integrity of the brickwork. Even if the fireplace is not used much then also dust and pollution can cause erosion of the mortar. Thus causing the bricks to become loose and eventually collapse. For this reason, during cleaning much emphasis should be given in inspecting the bricks and proper patches should be applied if necessary to maintain their solidarity.