A chimney needs to be swept because it is an exhaust system for your heating appliance. Having your chimney swept by a professional reduces the build-up of tar and other deposits which form on the internal walls of the flue way (generally caused as a result of incomplete combustion of the fuels used).
Areas of concern must be dealt with as a matter of urgency. Soot from coal, wood, oil, and gas-fired systems must be eliminated as well as obstructions such as birds nests, etc, removed and to ensure that the flue has not been partially or completely blocked as a result of debris falling down the chimney (generally caused by birds nesting or tiles, slates or masonry falling down the chimney stack).
An unswept flue can lead to poor combustion of your solid fuel resulting in at the very least an inefficient method of heating your home. In worst-case scenarios, it may also lead to a chimney fire or Carbon Monoxide poisoning.
Soot is classified as a hazardous product (it contains cancerous carcinogens) we use a state-of-the-art HEPA filter Sturdyvac vacuum with a 99.997% filtration efficiency.