13.1 This section only applies to installations where an opening has to be cut, or is being built into, the inner leaf of the cavity wall
(see Section 7.0 Non-Combustible Wall Installation).
13.2 To support the wall above the opening, a suitable lintel must be inserted across the top of the opening. If fitting into a cavity
wall, a lintel 876 mm long (minimum) having a height of 95 mm and a depth to match the inner wall thickness. The lintel could
be either precast concrete or steel.
Before proceeding with the installation of the heater, an assessment of the area immediately above the heater is required,
see Fig 10. If there are no existing openings or beams within either triangle, proceed with forming the opening. However, if
openings or beams occur within either triangle either :-
1.
Use the guidance in the Good Building Guide 10 to assess the loads,
2.
Seek specialist advice,
3.
Relocate the fire position.
The ‘Load Triangle’ - typical inner leaf weights
122 brickwork
104
kg
122
concrete blocks
110 kg
150
concrete blocks
146.5 kg
These are well within the load capacity of proprietary lintels.
13.0 GUIDANCE ON FITTING A LINTEL
Lo
ad
T
ria
ng
le
66
0
m
m
In
te
ra
ct
iv
e
A
re
a
11
48
m
m
420 mm
56
0
m
m
150 mm
Bearing
1 Brick
225 mm
The
Interactive
Area
The load Triangle
No Beam or
Opening in this Area
Top of hearth
50 mm above
floor level.
Lintel 876 (minimum) x 95 mm
Fig 10.
15
