WHY ?
If a chimney is in regular use, soot will build up in the flue and over time increase the risk of a chimney fire. If there is no appliance in place, the flue can smell, debris and soot can fall into the living space, making a mess.
Chimneys are easily blocked and particularly with gas fires, the risks posed are serious. If the fumes are unable to escape through the chimney, carbon monoxide will build up in the room, which can be fatal.
Even relatively small obstructions can inhibit the draw. For instance, some chimneys are prone to collecting cobwebs, which support layers of dust and debris. Chimneys without cowls often attract birds and squirrels – the nests they build are also a fire hazard. Occasionally, seeds dropped by birds or deposited by the wind will begin to grow in a chimney; this can result in damage to the brickwork.
Some chimneys have stainless-steel liners, which break down with age and need to be replaced. Typically, they will last 12 to 15 years, assuming the chimney is in use, and provided the right appliance is fitted to the correct liner.
Often, if changes have been made, some parts of the chimney will be incompatible with others. For example, if a gas fire is replaced with a multi-fuel stove, the old flue-liner will be unable to cope with the increased temperatures and the sulphurous chemicals in the soot. Also, the cowl will need better ventilation because the appliance will produce heavy, sulphurous smoke, rather than steam.
Occasionally, we have found that a chimney, with a live appliance in the fireplace, has been capped. Thus, before a new appliance is installed, it is important for a professional to inspect the chimney and issue a full safety certificate. This can be issued after a full chimney sweep.
If you make a claim based on a chimney-related problem, insurance providers will almost certainly want to see an in-date certificate.