Old chimneys are often very in-efficient and particularly if unlined, can leak products of combustion and tars through the chimney walls.
County Stoves experienced fitters have found It’s quite common to find that old chimneys are in a poor condition due to the flue surface and mortar joints being eaten away by corrosive condensates and soot deposits.
The size of the flue may also be too large to suit the operating requirements of many modern heating appliances. It was only in 1965 that Building Regulations required that all new chimneys had to be built with suitable flue liners of the correct flue size to protect the chimney structure.
County Stoves recommend you have any old chimney you are using checked for their condition and particularly if you are planning to re-open an old chimney after many years of not being used.
The check is best done by a chimney specialist and that’s where we come into our own. We start with the chimney being swept to make sure it is clear of obstructions such as dislodged masonry or bird’s nests. A smoke test is then carried out to establish whether there is any major fault that can cause products of combustion to leak through the chimney walls. The general condition of the chimney in terms of structural stability would also be checked, as well as making sure it is wind and water tight. Carrying out these checks should identify the repair work that is needed and more often than not, it is also necessary to have the chimney fitted with a new liner, which should improve both performance and safety. There are many factory made refining systems available and it is important to make sure that the correct flue size is fitted to suit the appliance or fire that will be used. Many of the same installation requirements as for new chimneys also apply.