Does your chimney need repairing? What exactly is a ‘broken’ chimney?
Chimneys are lined – the flue lining. This lining creates a clear path for the gas and smoke, and protects the fabric of the chimney from the products of combustion. In older houses this lining was usually clay. This weakens and breaks down after a few decades of use, particularly where a chimney hasn’t been cleaned regularly.
Modern flue lining come in different materials. A flexible steel liner can be lowered down the chimney to the hearth. Rigid steel liners are assembled in sections in the chimney. A ceramic coating can be sprayed on the inside of the chimney until an adequate layer of lining is created.
Each of these techniques has its pros and cons, price tags and level of guarantee for the future. A chimney sweep will be able to advise you on the best solution for your property.
How do I know if I need flue relining?
Flue liners are only needed if a chimney is defective – especially where smoke or fumes are leaking into the property. In this instance tar will build up inside the flue, often leading to staining on the chimney and house walls (inside and out). As the tar and creosote is highly flammable their presence can result in chimney fires – which won’t be covered by insurance if the chimney has not been regularly swept. There can be a risk of carbon monoxide poisoning through leaking gas, so flue relining is essential.
If you are installing a wood burning stove you might also need a flue liner to improve the efficiency of your chimney. To operate legally a stove needs a 65% efficiency rating at least. If the stove does not burn efficiently the tar produced by the low intensity burning will cause the problems to the chimney described above.
Contact a HETAs registered sweep and they will be able to advise you about chimney lining.