Fig. 15
A minimum 75mm thick Floor protector is only required if finished surface is combustible e.g: timber, carpet, tiles
Please note that these dimensions (based on Masonry margins) are the absolute minimum sizes - widths (A & B)
maybe increased if desired. If you intend on recessing the firebox, please add the recess value to Dimension ‘B’.
WARNING: Minimum cavity sizes leave NO MARGIN FOR ERROR . If the cavity is larger than minimum
dimensions (A & B) close up the lateral sides using hebel block, concrete block or similar (do not use any
combustible material).
Refer to Table 3 for the minimum cavity dimensions and temporary lintel height measurements, until the firebox and
flue system is installed. Note: Temporary lintel height is measured from finished floor protector level.
Ensure suitable air vents (min. 2 x 80mm diameter or equivalent) in place to vent firebox space - these maybe located
in the floor or in the side wall space; make allowance (min. 2 x 80mm diameter or equivalent) at the top of the chimney
chase, Pg. 14. Ensure vents are bird and vermin proofed.
CROSS SECTION
CAVITY PREPARATION
6.TMWG.10
Dra
wi
ng
N
ot
To
Scal
e
Flue pipe casing
recommended
SS Flue pipe
Rock-wool
insulation
min 2 x 100 x 50mm
or 80mm diam. wall
or
floor
mounted air
vents
min
Refer to Table 2 for
floor
protector dimension
if
floor
is made of combustible material
Concrete Lintel or
Hebel Block (lintel bar
may be required)
Lintel Bar
Rock-wool
insulation
Allow 2mm
clearance for
expansion
Ensure the
air intake is
unobstructed
100
B + recessed
Allow 5mm gap
around all four
sides of the firebox
to fit Stainless
Steel cover & allow
for firebox
expansion
RECESSED
REQUIRED 40mm Min.
- 100mm Max recess
Allow 5mm gap between plaster and flange to
ensure stainless steel cover can be fitted to the
box.
DO NOT PLASTER OVER THE FLANGE.
Jetmaster
Flange
All external air vents & ceiling penetrations must be
bird & rodent proofed with permanently
fixed screen
Fig. 17
Fig. 16
If recessing allow 2
mm for expansion of
the firebox
Don’t plaster over the flange
