Choosing the right fire

Brick chimney (Class 1) A brick chimney is recognised by a chimney stack with accompanying terracotta pot or gas terminal. These are the brick chimneys you get, mainly on older properties, that were to facilitate an open fire. They rely on the natural circulation of air to remove waste gases from the fireplace.
Pre-fabricated flue (Class 2) A pre-fabricated flue has a metal flue and terminal. A prefabricated flue will either be used on older properties where a chimney has been lined with a steel flue, or a newer property with a steel flue built in. They are made up of interlocking metal flue pipes. You can easily identify a prefabricated flue by the metal cowl on the roof, which looks like a thin metal chimney.
Pre-cast flue A pre-cast flue is built from concrete blocks and built into a property’s interior walls. They are a more common feature in new houses and can be recognised by a small ridge vent on the roof.
No chimney or flue If you have nothing on your roof, you probably have no chimney or flue. In this case, a balance flue will usually suit this situation when positioned on a suitable outside wall.