Flue Systems & Chimneys

Flue systems and Chimneys are the vital component for any wood burning or multi fuel stove, and should not be overlooked.  We stock a wide range of stainless steel liners, single and twin wall pipes.  We also deal with poumice flues like Anki and Isokern that allow you to create a new chimney stack, but without constructing an expensise chimney breast.

A chimney is a passage from the place of combustion to the outside world. Warm flue gases should rise through the passage to the point of exit. For a chimney to operate satisfactorily it should be smooth, warm and as straight as possible. If a chimney is irregular and rough, or cold and damp, the the flue gases will move slowly. Cooler gases will mean inadequate chimney suction and poor flue gas speed.

Wood burning stoves and multi fuel stoves work best when there flue passage runs directly from the outlet of the stove, all the way to the exit of the chimney, creating a single passage with no holes to give the best suction for the flue gases. 

Lining your Flue

We always recommend flue lining where possible for the following reasons: a flue liner will substantially decrease your chimney volume, consequently higher temperatures will be maintained and flue gases will travel faster, generating greater and more consistent draft. When possible, flue liners should be insulated to help with maintaining flue temporature and also this will reduce the chances of a warm liner coming into contact with existing tar (soot build up) within the flue passage which could ignite. Insulation can also reduce the noise that the flue gases travelling though the liner can create.

A warm flue will collect less deposit, therefore cleaning will be much easier to carry out. A lined flue, with its smooth surface, can be cleaned to leave the liner almost as clean as new. It is rarely possible to remove all deposits that accumulate in unlined flues, there are always holes and corners a brush does not reach.

For an existing chimney that is built from or lined with a clay liner we would still recommend lining your chimney with a stainless steel liner. However, a qualified and experience chimney sweep will be able to give you a report on the condition of your clay liner, and advise whether you should have it lined or not.  If you decide to not have your clay liner lined as they are in sound condition, you can use clay liner adaptors to connect your stove pipe to the existing flue.  

Twin Wall Insulated Flue

If there is no masonry chimney stack for you to utilise, you will be required to use a twin wall flue system to create a passage for the flue gases to travel to the outside world. Twin wall flue systems can be positioned anywhere throughout the house, dependant on where it is penetrating the ceiling and consequently what is above the ceiling, and also where it is coming out in relation to the roof. They can also penetrate a wall, and run up the side of your house. This tends to work best on a gable end of the house.

Twin wall systems can be bent/offset to avoid windows and ridge beams, but there are strick manufacturer regulations that need to be considered before building can carried out. The most effective and cheapest way to buy your twin wall flue system is to keep it as straight as possible. If you use bends/offsets, you will be building into the system, areas where the flue gases can slow and therefore on shorter systems, increase the risks of having poor suction. Also it be harder to clean through the flue with bends/offsets built in, and there will be an increase in price by almost the same amount as a length will cost.