Page 10
5. Flue & chimney requirements cont...
Ceiling penetration
clearances
Single skin flue
(stainless steel) must be completely enclosed with
single skin brickwork, concrete, or autoclaved aerated concrete
block. A chimney plate will be used to weather seal the chimney.
Twin skin flues
(stainless steel inner, and galvanised outer) can
either be left exposed or enclosed with stud walls and sheet plaster
or timber. A minimum of 50mm clearance must be maintained
between the outer flue and any combustibles within the chase or
ceiling cavity.
(Fig 5.1)
Position an active starter flue with two female ends to gather to
allow second length to have crimp facing down.
(Fig 5.2)
Glass tape may be required to ensure a snug fit.
The outer flue is then installed outside active flue with crimp facing
up to ensure water penetration on flue above roof runs out.
Rivet active flues together at crimped joins.
Fix outer non-active flues to active inner flues use 3 x 25mm self-
tapping screws through outer flue at bottom at each join and on top
at each join. As an alternative, rivet 4 x 25mm conduit saddles at
each join top and bottom.
Cowl
For solid fuel applications only, a rotating bird cowl will assist in
preventing the effects of downdraft as it turns with the direction
of wind.
(Fig 5.3)
Other solid fuel cowls may be desired to achieve a visual design
and such cowls can be used but must not restrict airflow from
the flue pipe casings.
Fig 5.2
Fig 5.3
Fig 5.1
Combustible ceiling
Combustible ceiling
Support angles
50mm gap from
Combustible materials
Outer Gal casing
Active stainless steel
Active stainless steel
Outer Gal casing
Crimped end down
From second length
Gather
Trim the crimp off first
length stainless pipe
Stainless Bird
Cowl
Cover cone
