Install Instructions
6
ENCLOSURE REQUIREMENTS 
Through Rooms: Interior vents shall be 
enclosed where they extend through closets, 
storage areas, occupied spaces, or any place 
where the surface of the vent could be 
contacted by persons or combustible materials 
except when installed in the room with the 
appliance. 
Multi-Story:  Consult local building or other 
applicable codes for requirements in your 
area. In the U.S., NFPA 211 10.6.3 (2013) 
states: “Vents that pass through the oors 
of buildings requiring the protection of 
vertical openings shall be enclosed within an 
approved enclosure. The enclosure walls shall 
have a re resistance rating of not less than 
1 hour where a vent is located in a building 
less than four stories in height. The enclosure 
walls shall have a re resistance rating of not 
less than 2 hours where a vent is located in a 
building four or more stories in height."
Figure 2
FIRESTOPS 
1.  Firestops are required at each ceiling/
oor penetration including an attic. 
Firestops are not required at the roof 
deck penetration.
2.  Cut and/or frame hole. (Table 3)
3.  Slide the two halves together and attach 
to the ceiling using either 8 penny nails 
or #8 1-1/2in wood screws at each of the 
four corners and at the two overlapping 
sides (Fig.2)
Table 3 - Wall & Ceiling Penetration Sizing Table
  VENT DIAMETER
Termination 2" 3" 4" 5" 6" 8"
CONCENTRIC
VERTICAL OR HORIZONTAL
4 ⁄" 
 105mm
5 ⁄" 
130mm
6 ⁄"
155mm
N/A N/A N/A
TWIN PIPE HORIZONTAL
CLASS IIB
7 ⁄" x 2⁄"
187mm x 
65mm
8 ⁄" x 3⁄"
212 x 85mm
9" x 4⁄"
228 x 100mm
N/A N/A N/A
TWIN PIPE HORIZONTAL
CLASS IIC (Framing Dimensions)
8" x 3"
200 x 77mm
8 ⁄" x 3⁄"
225 x 98mm
9 ⁄" x 4 ⁄"
238 x 112mm
N/A N/A N/A
SINGLE HORIZONTAL
CLASS IIB 
2⁄"
65mm /
3 ⁄" "
85mm 
4" "
100mm
N/A N/A N/A
SINGLE HORIZONTAL
CLASS IIC (Framing Dimensions)
 3"
77mm
 3 ⁄
98mm
4 ⁄
112mm
N/A N/A N/A
SINGLE WALL W/ LOCKING BAND
VERTICAL
3 ⁄" 4 ⁄" 5 ⁄" 6 ⁄" 7 ⁄" 9 ⁄"
SINGLE PIPE NO LOCKING BANDS
VERTICAL
3" 3 ⁄" 4 ⁄" 5 ⁄" 6 ⁄" 8 ⁄"










