TOA Electronics SSDV-3328 Horizontal Vent Termination Clearances, Roof Pitch Feet

Vent Termination Clearances

These instructions should be used as a guide- line and do not supersede local codes in any way. Install vent according to local codes, these instructions, the current National Fuel Gas Code (ANSI-Z223.1) in the USA or the current standards of CAN/CGA-B149.1 and -B149.2 in Canada.

Terminate multiple vent terminations according to the installation codes listed above.

Terminate single vent caps relative to building components according to Figure 5.

Vertical Vent Termination Clearances

TERMINATION HEIGHTS FOR VENTS ABOVE FLAT OR SLOPED ROOFS

Horizontal Overhang

Horizontal Vent Termination Clearances

The horizontal vent termination must have a minimum of 3" (76 mm) clearance to any overhead combustible projection of 2 1/2" (64 mm) or less. For projections exceeding 2 1/2" (64 mm), see Figure 6. All horizontal terminations may be located as close as 6" (152mm) to any combustible exterior sidewall. This distance may be decreased to 2" (51mm) if the SV4.5HT-2 or SF4.5HT-2 termination is used and the exterior sidewall is non-combustible only. For additional vent location restrictions refer to Figure 7 on Page 8.

Horizontal Vent Termination Clearances

		Combustible Projection	All horizontal terminations
	2-1/2 inches or less in length		may be located as close
	Combustible Projection		as 6” (152mm) to any
			(non-combustible and
greater than 2-1/2 inches in length			combustible) exterior
			sidewall. This distance
Ventilated			may be decreased to
Soffit	Unventilated		2” (51mm) for non-
	Soffit		combustible exterior
			sidewalls only, if the
			SV4.5HT-2 or SF4.5HT-2

2 FT MIN.

Vent

Termination

Storm Collar

Flashing

2 FT	Vertical
MIN.	Wall

Lowest

Discharge

Opening

H*

X

12

Roof Pitch is X/12

	3"	termination
	(76 mm)	is used.
18"	12"	Termination Kit
(457 mm)	(305 mm)

Termination Kit

		1 inch (25.4 mm) Minimum
Concentric		Clearance to Combustibles
	*H = MINIMUM HEIGHT FROM ROOF TO
Vent Pipe	LOWEST DISCHARGE OPENING OF VENT

The vent / air intake termination clearances above the high side of an angled roof is as shown in the following chart:

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 5

Note - See Figure 33 on Page 20 for the exterior wall recess allowances of the square horizontal termination.

Figure 6 Side Elevation View

NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.