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NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
VENT TERMINATION CLEARANCES
Gas Vent Rule - Gas vent caps are not per-
mitted within 8 feet (2.4 mm) of a vertical wall
or similar obstruction. Gas vent caps that are
located 8' or more from a portion of a building
which extends at an angle greater than 45°
upward from the horizontal may terminate in
accordance with (Figure 4 ), provided that in no
case shall any discharge opening on the cap be
less than 2' (610 mm) horizontally from the roof
surface (National Fuel Gas Code ANSI Z223.1
(NFPA 54) 7.6.2) (CAN/CGA B149).
Multiple Terminations
These appliances may vent adjacent to and at
the same level with any other gas appliances
(including direct-vent appliances) provided that
there is at least 2 ft. (0.6m) between the proximal
edges of the vent caps. These appliances may
be vented adjacent to a chimney vent servicing
a solid fuel fireplace provided the B-vent cap
is at least 2 ft. (0.6m) away from the nearest
point of the chimney opening.
Termination Heights For Vents
Above Flat Or Sloped Roofs
Ref. NFPA 54 / ANSI Z223.1, 7.6
Roof Pitch Feet Meters
Flat to 6/12 1.0 0.3
6/12 to 7/12 1.25 0.38
7/12 to 8/12 1.5 0.46
8/12 to 9/12 2.0 0.61
9/12 to 10/12 2.5 0.76
10/12 to 11/12 3.25 0.99
11/12 to 12/12 4.0 1.22
12/12 to 14/12 5.0 1.52
14/12 to 16/12 6.0 1.83
16/12 to 18/12 7.0 2.13
18/12 to 20/12 7.5 2.29
20/12 to 21/12 8.0 2.44
Figure 4 - Vertical Vent Termination Clearances
Roof Pitch is X/12
Minimum Height from Roof to
Lowest Discharge Opening
X
12
1“ (25 mm)
Minimum