You may already have a chimney liner but how can you tell if you may need a new chimney liner?
The most simplistic answer is that if your house was built before 1965, and you wish to use it for anything more than an open fire, then the odds are very good that you do in fact need a chimney liner. Older chimneys do degrade with time, with some degradation resulting in blocked chimneys. The simplest way of dealing with your concerns is to call out a certified chimney sweep to clean the chimney and advise you. A competent chimney sweep, who is HETAS registered will have the knowledge base needed to advise you properly, and sweeping the chimney will enable him to tell you what state it is in as well as the chimney liner. He will be able to tell you if you need a new chimney liner and advise on the most suitable liner..
There are a number of different types of relining systems on the market. All are different, and not all will suit your chimney.
The sectional chimney liner is made from terracotta, ceramics or pumice (the best) however, these require a lot of space within the flue to fit them, and a thorough installation may require that the installer break into the flue in several places to ensure that a proper job is done.
Next come pumped chimney liner. This is in effect a long rubber tube that is threaded down the flue, and cement is pumped around it to form a coherent liner. Once the cement has set, the tube is deflated and removed. In some cases, where the tube has not been supported properly, or the mix was not 100% properly mixed, this can leave bald patches and or cracks, thus making it a pointless exercise. You MUST always check these with a CCTV survey after the flue has dried for a couple of days before parting with your money.
Twinwall flexible liners are excellent methods of lining a chimney, especially for stoves, as they are small and can fit down the flues very easily. Stoves usually require no more than a 6 inch diameter flue, and you can see that this will pass down a 9 inch by nine inch flue with comparative ease.
Eldfast lining system. Open fires though do present a particular problem. When you reline their flues with a sectional chimney liner, the internal bore can easily drop below 8 inches, which can make all but the smallest open fires smoke. If you use the twinwall stainless liner, then the price increases RADICALLY with every inch increase in diameter. The Eldfast lining system merely coates the inside of the chimney with a ceramic paste, filling cracks and holes with ease to give an excellent finish. Best of all, it barely decreases the internal diameter of the flue, so if the flue pulled well with no smoking back before, it should function even better after the Eldfast chimney liner has been installed.
For further information on a chimney liner and an overview of the history of chimneys and liners, read our 7 part article