10
System Chimney
DISTANCE TO COMBUSTIBLES
In accordance with building regulations, it is essential that the correct distance to combustible
material is maintained. On
solid fuel
applications, where there is a risk of soot fire, a distance
of
60mm to combustibles
must be maintained within a
combustible floor
and within a
combustible shaft
(see Fig.1 below).There is no need to line the area within the floor cavity with
plasterboard; however the
ventilated fire stop plate
and
ventilated support plate
must be used.
On
gas and oil
applications, a distance of
50mm to combustibles
must be maintained within a
combustible floor
and within a
combustible shaft
. The
ventilated fire stop plate
and
ventilated
support plate
must be used.
Where the chimney penetrates a
non combustible
floor and where a
non combustible
shaft is
used, a distance of
50mm to the shaft
is sufficient. In this case,
non ventilated fire stop plates
and support plates may be used with a
ventilated fire stop
being used where the chimney
penetrates into the
roof space.
On bungalow applications where the chimney runs through either a combustible or non-
combustible ceiling, an unventilated bungalow fire stop plate kit can be used. Please note that
an unventilated support plate can not be used above the ceiling in this case. The weight of the
chimney should be supported using the roof support (see p.33). Distance to combustibles must
be respected within the ceiling space (see Fig. 2 below) and mesh frame should be used within
the loft space, which must be ventilated (see Fig. 2 below).
ENCLOSURE/SHAFTS
With the exception of the room containing the appliance, where the chimney passes through
any part of the building, where there is a risk of accidental human contact, i.e a bedroom etc., or
where there is a risk of contact with combustible materials stored in a cupboard or in the roof-
space, the chimney must be enclosed in an appropriate way to meet Building Regulations. This
can be achieved by boxing in the chimney in habitable rooms, or by the use of a protective wire
mesh frame in roof spaces etc. In all cases the minimum distance to any combustible material,
including loft insulation, must be respected according to the table on p.10, and any enclosure
should be ventilated using the appropriate ventilated fire stops (see p.22).
Fig. 1
Fig. 2
Internal House
Combustible Floors
Internal Bungalow (Ventilated Loft Space)
Combustible and Non-Combustible Floors
