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4:FLUES AND BUILDERS OPENING REQUIREMENTS
4.1
Prior to creating the builders opening the flue must be checked.
No restrictor plate or flue damper is permitted.
The flue must be swept prior to installation.
The flue must be free of any obstructions.
The flue must be checked to ensure it
only
serves the fireplace opening to be used for the fire.
The flue must have a positive up-draught and checked as follows before the builders-opening is constructed
Any under floor air supply to the fireplace must be completely sealed off
Before installing the fire a simple smoke test should be carried out on the flue to check its condition. Light a smoke
Generator, hold it at the top of the fireplace opening and observe that the smoke is being drawn up the flue, if so,
proceed with installation. If not, pre heat the Flues for a few minutes and recheck, if smoke still fails to be drawn up the
flue, further Investigation is required and the appliance
MUST NOT BE FITTED
.
Minimum diameter circular flues 125 mm
Minimum effective height of all class 1 (175mm) flues 3 metres
Minimum effective height of all class 2 (125mm) flues 4 metres
WARNING PASSING A SMOKE TEST IS NOT AN INDICATION THE APPLIANCE HAS PASSED A SPILLAGE TEST
BOTH TESTS ARE A SEPARATE PROCEDURE
4:2
Purpose Made Builders Opening With a Conventional Stone Flue.
With a minimum cross sectional dimension of 175mm (7”) and minimum effective height of 3 meters.
The base of the builders opening must be a non-combustible material and at least 12mm thick. The Builders
Opening must be at least 300mm off the floor for a wall mounted fire installation.
It is recommended that a qualified builder construct the builder’s enclosure.
A lintel should be used to support the chimney breast above the
Builders opening.
Any gaps around the Builders Opening, as may be the case with a dry liner wall must be sealed.
4:3
Additional Requirements for a Purpose Made Builders Opening with a Flexible Flue Liner or
A 125mm (5”) diameter flexible gas flue liner with effective height of 4 metres
Conforming to B.S 715, and connected to a Register Plate fitted and sealed above the Builders Opening.
4:4
A solid flue pipe 125mm(5”) diameter and metal flue box conforming to B S 715 with effective height of 4
metres
4:5
SHELF POSITION
If the fire is to be installed into a suitable fire surround it must have a fire rating of 150C.
If the fire surrounds has a combustible shelf it must be at least 200mm above the top of the fire
And protrude from the wall be no more than 150mm
For every 25mm increase in depth of combustible Shelf the position of the shelf must be raised by a further
15mm.
