8
Point where flue passes through
weather surface (Note 1,2)
Clearances to flue outlet
At or within 600mm of
the ridge.
at least 600mm above the ridge
Elsewhere on a roof
(pitched or flat)
At
least
2300mm
horizontally from the
nearest point on the
weather surface and:
a) at least 1000mm above the
highest point of intersec on of
the chimney and the weather
surface: or
b) at least as high as the ridge.
Below (on a pitched roof)
or within 2300mm
horizontally to an
openable rooflight or
other opening. (Note 3)
at least 100mm above the top
of the opening.
Within 2300mm of an
adjoining or adjacent
building, whether or not
beyond the boundary.
(Note 3)
at least 600mm above the
adjacent building.
Notes:
1) The weather surface is the building external surface, such as its
roof, les or external walls.
2) A flat roof has a pitch less than 10°.
3) The clearances given for A or B, as appropriate, will also apply.
4) A ver cal flue fixed to an outside wall should be treated as an
equivalent to an inside flue emerging at the nearest edge of the roof.
Flue outlet posi ons
The flue outlet should be above the roof and in such a posi on where the products of combus on may be
discharged freely whatever the wind direc on. The discharged products of combus on must not present a fire
hazard. Great care should be taken where the weather surface may easily ignite.