Flueing
Which Type of Chimney or Flue do I have?
Brick Chimney
The Classic brick built chimney is suitable for all open flued gas fires. As these chimneys are deep you can choose a full depth fire through to the shallow slimline products. A brick chimney is recognised by a chimney stack, with either a pot or gas terminal on your roof. Also you will have a chimney breast either inside the room or on the outside wall for the fire to fit into. The diameter of the flue is a minimum of 7″ (175mm) or greater. The brick built chimney or a 7″ flue liner is also known as Class 1.
Prefabricated (Class 2 ) Flue
Pre-fabricated flues are suitable for most gas fires and gas stoves. Prefabricated flues offer a good depth so you can also choose from the majority of full depth fires and all slimline fires. Pre- fabricated flues are found either in older houses where the existing Chimney has been lined by a steel flue or a newer house with a steel flue built in and is recognised by a metal flue and terminal on the roof. The diameter of the flue is a minimum of 5″ (125mm). Some older houses where the brick chimney is unsafe will be lined with a 5″ (125mm) flue. A pre fabricated flue with a minimum diameter of 5″ (125mm) is also known as Class 2.
Precast Flue
Pre-cast flues are found in many modern homes and can be suitable for slimline gas fires subject to inspection and testing. Pre-cast flues are recognised by a ridge vent or metal flue terminal on the roof. The Flue is constructed from concrete or clay blocks, they form a rectangular section flue and are very shallow in depth.
Balanced Flue
A balanced flue gas fire is a glass fronted gas appliance which vents directly through an outside wall. They are an efficient type of gas fire and are usually recommended for use where there is no chimney or flue available. No mains electricity is required.