10
INSTALLATION IN TIMBER FRAME BUILDINGS
PF MODELS
These instructions are to serve as guidance only,
since the construction of timber frame buildings
varies from site to site. It is important to note that
where removal of any part of the inner timber leaf
of the wall is involved, the structural integrity of
the wall must be maintained and the advice of
your local Building Control Department should be
sought. Guidelines should be sought from IGE/
UP/7 Gas Installations In Timber Frame Buildings.
If the property is under any form of N.H.B.C. cover,
it is advised that their advise on this modification
to the property should also be sought.
Either of the following 2 methods of installation
may be adapted for use in timber frame buildings
providing extra care is taken to protect
combustible materials from contact with hot
surfaces.
pecial attention must be paid to the location of
the studwork frames of the inner leaf and the
appliance positioned accordingly. Wires and pipes
that run within the inner timber leaf must also be
located and taken into account when positioning
the appliance.
METHOD 1 :: EXTENDED FIRE SURROUND OR
FALSE CHIMNEY BREAST
50 mm clearance must be provided from the
appliance case sides, rear and base, and 100mm
clearance from the appliance top to any
combustibles. These clearances must be
maintained by the presence of a purpose provided
cavity box.
The cavity box should be constructed from 12mm
upalux
®
or equivalent material and be fixed with
min. internal opening dimensions of 700mm high x
470mm wide x 232mm depth. A hole of 200 mm
diameter must be cut in the back of the cavity box
concentric with the flue duct when the appliance is
installed.
A 200mm diameter metal sleeve concentric with
the flue must be provided to pass through all the
combustible layers of the wall. This sleeve must
be a tight fit in the hole in the cavity box and must
not overhang the wall cavity by more than 5mm.
The vapour barrier on the back of the inner timber
leaf should be carefully cut and fixed to prevent
ingress of damp into the plasterboard layer.
The void around the appliance sides, back and flue
when positioned in the cavity box must be packed
with 50mm of Rockwool
or equivalent material
and the top must be packed with 100mm of
Rockwool
. NOTE: The Rockwool
must not
overhang the wall cavity.
The fan unit must not be installed into any
combustible materials. If the outer layer of the
wall is combustible then the fan unit must be
surface mounted using the spacer (optional extra)
with a 12mm upalux
®
pad between the spacer
and the wall surface. The 200mm diameter sleeve
must also extend through the whole of the wall
and finish flush with the outer surface.
METHOD 2 :: WHEN SETTING THE APPLIANCE
INTO THE INNER TIMBER LEAF OF THE WALL
Find a suitable position between the wall panel
frames and carefully open up a hole to allow the
fixing of the cavity box referred to below, paying
careful attention to securing the damp proof
membrane back into position.
50 mm clearance must be provided from the
appliance case sides, rear and base, and 100mm
clearance from the appliance top to any
combustibles. These clearances must be
maintained by the presence of a purpose provided
cavity box.
The cavity box should be constructed from 12mm
upalux
®
or equivalent material and be fixed with
min. internal opening dimensions of 700mm high x
470mm wide x 232mm depth. This box should not
bridge the cavity but if this cannot be avoided then
a waterproof membrane must be placed between
the rear of the cavity box and the outer skin of the
dwelling. If this membrane is combustible or there
are any other combustible materials located
behind the cavity box then a hole of 200mm
diameter must be cut in the back of the cavity box
concentric with the flue duct when the appliance is
installed.
A 200mm diameter metal sleeve concentric with
the flue must be provided to pass through all the
combustible layers of the wall. This sleeve must
be a tight fit in the hole in the cavity box and must
not overhang the wall cavity by more than 5mm.
The vapour barrier on the back of the inner timber
leaf should be carefully cut and fixed to prevent
ingress of damp into the plasterboard layer.
The void around the appliance sides, back and flue
when positioned in the cavity box must be packed