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How To Install a Flue

If your chimney duct is going to run straight up through the ceiling and roof, you will be particularly interested in learning how to install a flue internally.

This is the most common installation method in South Africa and it starts with a single wall flue from the fireplace running up towards the ceiling. When a fire is burning, the first chimney duct still contains scorching hot fumes, so it provides welcome additional heat to the room –just be careful not to burn yourself! As the flue duct approaches the ceiling, single to double adapter rhino-boards are used to transition from single wall piping to double wall,= insulated piping, which is what is used to run the flue safely through the roof cavity. The insulation in the double wall flue stops the outside of the piping from getting too hot, and prevents combustible materials in the roof from excessive heat and potentially catching alight. In the hidden area of the roof cavity it is difficult to regularly inspect and monitor the condition of the flues and insulation material, so for your peace of mind and ongoing protection it is preferable and safer use a high quality, double wall insulated stainless steel flue.

However, you need to install your flue externally if you plan on having your chimney duct run through the wall and on the outside of the house. In this case, piping bends are used to direct the flues out through an external wall. Then the ducts are typically run upwards along the wall using wall fixing brackets. While this installation method is usually more labour intensive, the major benefit here is that the flue ducts run far away from any combustible materials, so it is safe to use single wall flue piping instead of double wall pipes, and consequently reduce costs.