Where removal of any part of a timber frame is undertaken the structural integrity of the wall must be retained. The
advice of your local building control officer should be sought. If the property is under any NHBC warranty it is also advised that
their advice on this kind of modification is sought.
Either of the two preceding installation methods may be adapted for timber framed buildings, providing extra care is taken in
ensuring combustible materials are adequately protected from the effects of heat.
The appliance must be installed in accordance with the British Gas documents DM2 and DM3 or the Institute of Gas Engineers
published procedure document IGE/UP/7.
Special attention must be paid to the location of studwork frames of the inner leaf and the appliance positioned accordingly. Wires
and pipes that run within the wall must also be taken into account.
Installation as per method 1
(against inner wall)
When using this method of installa-
tion the following amendments
should be incorporated. A 75mm air
gap or 75mm of insulation (e.g.
rockwool) must be provided
between combustible materials and
the sides and rear of the cavity box.
A 100 mm air gap or 100mm of
insulation (e.g. rockwool) must be
provided to the top of the cavity
box. It is also a good idea to enable
as much airflow as possible, into and
out of the area behind the fire with-
out excessive heat loss from the
room when the fire is off.
Installation as per method 2 (recessing into a wall)
When setting the appliance into the
wall find a suitable position between
frame timbers and open up the hole.
Secure back the damp proof mem-
brane to prevent ingress of damp.
Again 50mm insulation plus a 12mm
thick fire retardant board, 'Superlux'
or equivalent, must be provided
between combustible materials and
the sides and rear of the cavity box.
100 mm of insulation plus a 12 mm
thick fire retardant board, 'Superlux'
or equivalent, must be provided to
the top of the cavity box. The
exposed cavity should be sealed off
using non-combustible board, ('Supalux' or equivalent), made into a 4-sided box. It is also good practice to further insulate the
cavity with a 50mm layer of Rockwool outside the Superlux box. Note that the appliance should not be allowed to bridge the
cavity in this installation method. It is also a good idea to enable as much airflow as possible, into and out of the area behind the
fire without causing excessive heat loss from the room when the fire is off.
Figure 8
Outer leaf of building
Non combustible back panel
Combustible inside
wall of building
Rockwool insulation 75mm sides
and rear, 100mm top
False chimney breast
50mm of Rockwool to insulate cavity
Superlux Box, 12mm thick, External dims;
Height 677, Width 529mm, Depth 167mm.
Rockwool insulation, 50mm sides
and rear, 100mm top.
Combustible inside
wall of building
Figure 9
©
2013 Focal Point Fires plc.
6.5 INSTALLATION METHOD 3
(timber framed buildings)
GB IE
8
