4 The Hearth (Appliances in floor level fireplaces)
Where the appliance is fitted in a floor level builders opening, floor level fireplace recess
or floor level flue box, the hearth shall:
a) Extend through the whole base of the builders opening, fireplace recess or
beneath the flue box.
b) Project at least 300mm in front of any naked flame or incandescent part of
the fire bed.
c) Project at least 150mm beyond each side of any naked flame or incandescent
part of the fire bed, or if there is a non-combustible wall within 150mm of any
naked flame or incandescent part of the fire bed, up to that wall.
d) Have a thickness of not less than 12mm and a minimum height of 50mm
along its front and side edges.
Hole-in-the-wall installations
Where the appliance is installed in a hole-in-the-wall fireplace, a hearth as previously
detailed for floor level fireplaces shall be fitted on the floor beneath the hole so as to
protect combustible material from radiant heat.
a) If a hearth is not to be used, so as to maintain a minimal and contemporary
styling, the appliance must be installed so that every part of any naked flame
or incandescent part of the fire bed is at least 225mm vertically above any
carpet or floor covering.
b) Where no hearth is to be fitted consideration should be given to fixing a
tactile separator to protect young children, the elderly and the infirm. A
tactile separator can be in the form of a fender, kerb, hearth, shelf or
horizontal bar all made from non combustible material and fixed not less
than 50mm & not more than 1000mm above the floor level. They should be
positioned not less than 300mm in front of and 150mm beyond the edge of
any naked flame or incandescent part of the fire bed.
5 The Chimney Flue
Both Appliances The chimney should be of the open-flue type and have a minimum
cross sectional dimension of not less than 175mm.
The flue must have a minimum effective height of 3 metres.
No restrictor plate or flue damper is permitted. Where a variable damper is fitted, this
must be removed.
The chimney must be swept before the appliance is fitted.
500 Model This model may also be connected to 125mm diameter flue liner or twin wall
gas flue using the optional gather and the 125mm adaptor.
6 Optional Gather
An optional gather is available for both appliances to connect to a flue liner or a twin
wall metal chimney. The dimensions of the gathers are given in Figure 3. Check the
thickness of any masonry plus the decorative infill panel, if used, against the distance
shown between the rear of the flange and the front of the gather. The gather should be
installed before the firebox is finally placed in position and temporarily lodged in
position. After the firebox is properly positioned the gather can be drawn down to the
firebox by gripping the handles provided inside the gather and secured with five self
tapping screws which pass through the top of the firebox into the gather. Please note
that the gather and firebox are not structural items and the flue connected should be
supported and not rest entirely on the gather.