NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
23
V
H2
H1
H
Wall Firestop/Spacer
(SV4.5HF)
Ceiling
Firestop/Spacer
(SV4.5VF)
When using Secure Flex,
use Firestop/Spacer
SF4.5VF.
When using Secure
Flex, use Firestop/Spacer
SF4.5HF.
V
H
H1
V1
Wall Firestop/Spacer
(SV4.5HF)
Ceiling
Firestop/Spacer
(SV4.5VF)
When using Secure Flex,
use Firestop/Spacer
SF4.5VF.
When using Secure
Flex, use Firestop/Spacer
SF4.5HF.
Wall Firestop/Spacer
(SV4.5HF)
Table K
H
+ H
1
+ H
2
Maximum
H
Maximum
V Minimum
feet
(meter)
feet
(meter)
feet
(meter)
5
(1.524)
2
(0.610)
1
(0.305)
10
(3.048)
4
(1.219)
2
(0.610)
15
(4.572)
6
(1.829)
3
(0.914)
20
(6.096)
8
(2.438)
4
(1.219)
V + H + H1 + H2 = 40 feet (12.2 m) Max
H = 8 feet (2.438 meters) Max.
H + H1+ H2 = 20 feet (6.096 meters) Max.
Example:
If 20 feet total (H+H
1
+H
2
) horizontal vent
run is needed, then 4 feet minimum of (V) vertical
vent will be required.
This table shows a 1(V) to 5(H) ratio. For every
1 foot of (V) vertical, you are allowed 5 feet of
horizontal run up to a maximum total (H+H
1
+H
2
)
horizontal run of 20 feet.
Figure 40
-
Top Vent - THREE 90 DEGREE ELBOWS
Figure 39
- Rear Vent - THREE 90 DEGREE ELBOWS
See Table 12 on Page
21 as an aid in venting
component selection for
a particular range of exte-
rior wall thicknesses.
See Table 12 on Page 21 as an aid in venting
component selection for a particular range of
exterior wall thicknesses.
HORIZONTAL VENT FIGURES / TABLES (CONTINUED)
Square termination
(SV4.5HT-2) shown.
Square termination (SV4.5HT-2) shown.
Table L
H
+ H
1
Maximum
V Minimum
feet
(meter)
feet
(meter)
5
(1.524)
Elbow Only
5
(1.524)
1
(0.305)
10
(3.048)
2
(0.610)
15
(4.572)
3
(0.914)
20
(6.096)
4
(1.219)
H
+ H
1
= 20 feet (6.096 m) Max.
V
+ V
1
+
H
+ H
1
= 40 ft. (12.192 m) Max.
Example:
If 20 feet total (H+H
1
) horizontal vent
run is needed, then 4 feet minimum of (V) vertical
vent will be required.
This table shows a 1(V) to 5(H) ratio. For every 1
foot of (V) vertical, you are allowed 5 feet of (H+
H
1
) horizontal run, up to a maximum horizontal
run of 20 feet.
An elbow is acceptable as 1 foot of vertical rise
except where an elbow is the only vertical com-
ponent in the system. See
Figure 35
.
