13
INSTALLATION: GENERAL GUIDELINES
Please refer specifically to current building regulations
which apply to your country or region Adopt
whichever provides the highest / safest margin.
The Hearth
The hearth should be made of solid non-combustible
material, set on a firm and level base and should be at
least 125mm (5”) thick. This can include the thick-
ness of any non-combustible floor under the hearth
or non-combustible decorative surface. It must be
capable of supporting the weight of the stove (when
loaded) along with any attached flexible flue liner
which may bear down on the stove. This hearth must
conform to local building regulations which may vary
from country to country.
In England and Wales there is a minimum requirement
for the hearth to project 500mm (20”) in front of any
brick or stone recess and 150mm (6”) at each side of
the recess. The hearth should extend by a minimum
of 225mm (9”) from the front of the stove (which
includes the edge of the ash lip). As a general rule it is
best to extend the hearth to at least 75mm (3”)
beyond the furthest out-swing of the stove door if
possible to avoid any potential live ash held on the
inset door falling on to combustible flooring or floor
coverings. If the top of the hearth and any combus-
tible floor coverings are level with each other then a
retaining fender should be fitted to warn occupants of
the hearth area. Alternatively, a 28mm (1.1”) change
in level provided by a decorative non-combustible
material such as stone, marble, granite, ceramic tiles
etc could be used.
Please note that some materials, such as marble, may
not be suitable when used in a single sheet. This may
prove problematic if, for example, the inset stove is
being installed within an existing fire surround which
features a one-piece back panel which the inset stove
is intended to sit inside. Non-combustible fire
surrounds intended for use with solid fuel open fires
and stoves feature smaller panels pieced together
which allow space for expansion when hot. Your stove
dealer or installer should be able to advise you about
the suitability of an existing fire surround.
The ‘Fireplace’
The stove must be sited within a brick or stone fire-
place recess. It is unsafe to use this inset stove as a
free-standing stove.
The fireplace side and rear walls should be at least
75mm thick and made of non-combustible brick or
stone. Any gaps at the back and sides of the stove
and the fireplace aperture should be filled with non-
combustible insulation material such as rockwool or
vermiculite. This will not only improve the efficiency of
the stove but also help avoid the potential build-up of
combustible soot along the sides – this is an especially
important requirement if you are not using a flue liner.
Flue Draught
The minimum flue draught requirement for the
GR357i Graphite Inset is 4.5g/s.
The Chimney, Flue and Flexible Liners
Other appliances should not share or be connected to
the same flue system or chimney.
Generally speaking, the chimney or flue terminal
must be above the height of the apex of the building
and any other obstructions, such as trees, which are
within 3m (10’) of the flue terminal. Failure to do this
could affect the efficiency of the stove and may also
cause unwelcome down draughts which would mean
potentially dangerous flue gases could be emitted into
room.
If you are using an existing chimney and it has been
checked for condition and suitability (see below), in
the interests of safety you must ensure that it is swept
before the stove is installed, even if it has never been
used or you intend to use a flexible liner. To find a
local registered sweep visit The National Association of
Chimney Sweeps at
www.chimneyworks.co.uk
or the
Guild of Master Chimney Sweeps at
www.guildofmasterchimneysweeps.co.uk
.
The recommended minimum height for the chimney
/ flue system from the top of the hearth base to the
top of the chimney terminal is 4.5m (15’). If this is not
possible then a ‘spinner’ type cowl, to compensate for
any potential limited up-draught, should always be
specified and specialist advice sought on the correct
type.
Under no circumstances should the stove’s 150mm
(6”) diameter flue be reduced in any part of the flue
system as this could cause a build-up of dangerous
carbon monoxide gas.
When your new inset stove is installed with a flexible
flue liner it should be possible to sweep the chimney
through the stove by simply removing the baffle plate
inside the ‘roof’ of the stove. However, if you do not
use a liner the installer should, if possible, provide an
alternative means, such as a soot door with adequate
air-tight seal, in the chimney wall to be able to clean
the whole of the chimney / flue system.
Since stoves create flue gases at a much greater
temperature than those produced by an open fire or
gas appliance it does not necessarily follow that your
chimney will function adequately (or safely) when
your new stove is installed. The best way to ensure
that you have a fully functioning flue system is to fit
an approved flexible multi fuel flue liner.
Graphite strongly recommend fitting a chimney liner
for the following reasons:
• A flue liner is a major ‘quantifiable’ component in
a total and fully functioning flue system. As such it
will provide a consistent flue draught from the stove
through to the chimney terminal and when back-filled
