What type of chimney/Flue do i have?

Brick Chimney/Class 1

Typically these are found on older properties and they tend to be the traditional brick chimney style. For the most part their purpose was to facilitate an open fire and they would require natural circulation to take the waste gases away from the fireplace.

For homes with a Class 1 Chimney there doesn’t tend to be many restrictions on the type of fireplace but it is important that the chamber itself has enough room to house the fireplace. It may be that a traditional chimney requires a liner as it may not be sealed depending on the age of the property.

PreFabricated Flues/Class 2

This kind of chimney/flue may be found on an old property in circumstances where the chimney has been fitted with a steel flue liner. A prefab flue could also be found on a newer home which has a built-in steel flue. Homes with prefab flues are easily identifiable by the metal cowl on the roof. The flue itself is comprised of metal flue pipes which interlock.

It is possible to have a gas, gel or electric fireplace with a prefabricated flue however they aren’t designed to handle solid fuel fires.

In many situations the diameter size of the flue has an influence on the type of fireplace, for instance 7 inches or more will require a Class 1 fire and 5 inches will need require a Class 2 flue.

Precast Flue

Many modern houses built after 1960 do not have a class 1 brick chimney but are fitted with a precast chimney system identifiable by a ridge vent or gas terminal through the roof slope. A precast flue is built from gas flue blocks which are built into and bonded with the inner leaf block work of an external wall, is allows the fires to be installed within a partition or party wall or external wall. Due to the nature and type of construction precast chimneys tend to be shallow in depth.

No Chimney or Flue

If a property doesn’t have a chimney it doesn’t necessarily mean that a fireplace isn’t an option. While an electric fire is always an option as they don’t require a chimney there are other options:

Balanced Flue Gas Fires/Closed Combustion Gas Fire – these fires use two pipes – one to extract fumes away and one to supply air to aid combustion. They need to be installed in rooms with an external wall. (the outside of house has to be the owners property)