Flues for Wood Burning Stoves
Installing a flue pipe for your log burner is essential. The types of flues for wood-burning and multi-fuel stoves include flexible flue liners, single-skin flues, insulated flues, and twin wall flues.
Types of Wood Burning Stove Flues
The log burner flue pipe is available in a number of different materials – stainless steel, concrete, pumice, clay, ceramic, and plastic. Concrete, pumice, clay, and ceramic are collectively referred to as masonry chimneys. Plastic flues are only allowed to be used for low-temperature condensing applications.
Care must be taken to check the designation of stainless steel chimney systems and flexible liners, as a limited number are specifically designed for use with gas-fired appliances. These must not be used with wood burning or multi-fuel appliances. Clay and pumice chimney systems and liners are suitable for wood, multi-fuel, oil, and gas.
Concrete gas flue blocks, as the name suggests, are only to be used with gas-effect fires and must not be used with wood or solid fuel fires.
The terms flue and chimney flue are often used interchangeably, though this isn’t necessarily correct.
A flue is a duct or pipe that transports exhaust gases. A flue works under negative pressure, drawing the product of combustion from the appliance. A chimney flue is specifically the duct or pipe placed within the chimney system to transport said gases.
Flexible Liners for Wood Burning Stove Flues
Stainless steel flexible liners are certified to BS EN1856-2.
Flexible liners are used to reline an existing chimney. Care must be taken when selecting a flexible liner. There are two types of flexible liners:
- Single skin liners for use with gas appliances
- Twin skin liners are manufactured from overlapping strips of high-grade stainless steel to give a smooth, sealed flue-way. These liners should be used as a log burner flue for a wood-burning stove or multi-fuel appliances. Single skin liners must never be used as log burner flue.
Stainless Steel Flue Pipe for a Wood Burner
Insulated stainless steel system chimneys (also called twin wall flues) consist of two round, stainless steel metal walls with insulation filling the annular space between them. Some systems have a ceramic liner.
Factory-made steel systems are easy to handle and available with a wide range of fittings, such as elbows, terminals, and tees, all of which simply lock together. They are easily assembled and fixed with a locking band. These products, which can be used internally and externally, must be certified to BS EN 1856-1:2009.
Stainless steel flue systems tend to be used in existing buildings that do not have existing chimney flues and extensions because they do not require a dedicated foundation and can be easily retrofitted.
Connecting Flue Pipes
Connecting flue pipes are designed to connect the appliance to the flue. The pipe is usually decorative because it is visible in the living area. The stove chimney pipe options are vitreous enamel or single-wall stainless steel.
Single-wall stainless steel is certified to EN1856-2. The vitreous enamel coating should comply with the recommended requirements for high resistance to heat in BS1344 part1:1994 part 7:1984 and acid resistance BSEN 14483-1:2004. The European Standard for vitreous enamel low-carbon steel flue pipes is BS60009-1989.