Frequently Asked Questions

 

 

We get asked so many questions with regards to wood burning or multi-fuel stove installations, "Do I need a flue liner"? "Can I burn paletts on the fire"?. Please find below the most common questions asked when it comes to solid fuel appliances.

 

Do I need to line my chimney?

 

In the Building Regulations Approved Document J (ADJ), paragraph 1.36 gives guidance on why a chimney might need to be relined and how to check a chimney. Refer to the appliance manufacturer’s instructions to see if the appliance is suitable for use with an unlined chimney. Once it is decided that an existing chimney is to be re-used or the appliance being served by the chimney is to be changed for a different type or one of a different rating the chimney may need to be altered. In order to ascertain whether the chimney is suitable or if a new lining is necessary the chimney and its flue should be checked by a competent chimney engineer, preferably a member of the National Association of Chimney Engineers (NACE ). There will be one of three reasons why the existing chimney may need to be re-lined.

 

A chimney will need to be relined if (1) It is found to be unsound from the results of the appropriate test in accordance with Appendix E of ADJ.

 

And/or (2) If the cross-sectional area of the flue is too large for the intended appliance.

 

And/or (3) Any existing lining is found to be unsuitable for the proposed appliance type.

 

D Clarke & Son will always install a flue liner with a new installation. The chimney will be swept prior to fitting. We can then guarantee the operation and performance of the installed product.

 

 

What can my chimney be lined with?

 

Rebuilding or relining an existing chimney requires specialist advice. Providing the existing chimney structure is sound, there is a wide choice of factory made chimney relining systems that can be used.  Fire-resistant precast concrete, clay and pumice flue liners or ceramic liners offer the most permanent solution, providing the existing chimney openings are big enough to take the correct flue size to suit the proposed appliance.  Cast In-Situ lining systems are also available (see Section J of Part 2 of the HETAS Guide) which have been tested by an independent body, such as HETAS or BBA, to meet the appropriate requirements of BS EN 1857:2003  at the T400 N2 D 3 G level using tested materials which are installed under an accepted Code of Practice.  It is desirable for such installations to be independently monitored under a QA inspection system.

Double skin flexible stainless steel flue liners offer an alternative answer if access is difficult or the existing chimney is unable to accept other types of liners.  However, these flexible liners, whilst being easier to install and replace, are not permanent and significant periods of slow burning with solid fuels or infrequent chimney sweeping can cause corrosion damage which reduces the expected life to less than 5 years. Under no circumstances should a single skin flexible liner designed solely for use with gas fires be used with a solid fuel burning appliance. The efficiency and life expectancy of any chimney is dependent on correct use and maintenance. Masonry and precast chimney products whilst usually offering long life and high resistance to risk of corrosion, tend to involve more installation work, when compared with metallic chimney systems.

Metal liners and insulated metal chimneys offer fast and convenient installation. However, they are less resistant to damage by corrosion particularly if subjected to abuse or inadequate cleaning.  Allowing soot or condensate deposits to accumulate in metal lined chimneys and also prolonged periods of burning solid fuel slowly in slumbering conditions, particularly on closed appliances, can cause high concentrations of corrosive condensates to build up and attack the metal liner. This situation can considerably reduce the life of the flue lining.

 

How often should I get my chimney swept?

 

A chimney or flue liner should be swept at least once annually when burning authorised smokeless fuels and at least twice a year when burning wood or bituminous coal.