INSTALLER’S GUIDE
Page 10
Figure 2. Fireplace catchment
space
The flue, measured from the bottom of the fireplace
opening to the bottom of the terminal, shall be not
less than 3m in actual vertical height. When
calculated in accordance with BS 5440: Part 1
Annex A, the minimum
equivalent
height of the
flue shall be 2.0m of 125mm dia. flue pipe.
4.10.2
The flue must be clear of any obstruction
and its base must be clear of debris.
4.10.3
The flue must be completely sealed so that
combustion products do not come into contact with
combustible materials outside the chimney.
4.10.4
The flue must serve only one fireplace.
4.10.5
Proprietary terminals must comply with BS
715 or BS 1289. Any terminal or termination must be
positioned in accordance with BS 5440 Part 1 to
ensure that the products of combustion can be safely
dispersed into the outside atmosphere. Where the
appliance is connected to an unlined brick chimney it
is generally unnecessary for the chimney pot to be
replaced or for a terminal to be fitted unless the flue
has a diameter smaller than 170mm.
4.11
If the fireplace opening is an underfloor draught type, it must be sealed to stop
any draughts.
4.12
The flue spigot and any spigot extension must be capable of passing through the
closure plate by at least 25mm with a minimum clearance of 50mm between its open end
and the nearest obstruction.
There must also be a minimum clearance of 165mm between the back of the closure plate
and the back of the catchment space.
The catchment space below the flue spigot must extend at least 250mm downwards
measured from the bottom of the flue spigot.
See figure 2.
4.13
The front of the fireplace should be flat over an area sufficient to ensure a good
seal with the closure plate. The flat surface should extend for a height equal to that of the
closure plate plus 20mm and for a width equal to that of the closure plate plus 40mm.
