Desa (V)DVF36 - Manual (Page 16)

www.desatech.com 56131-F 16
VENTING INSTALLATION
INSTRUCTIONS
Continued
Figure 26 - Installing Firestop
If area above is a living space, install
firestop below framed hole.
If area above is an attic, install firestop
above framed hole.
Note: Pay special attention to these installa-
tion instructions for required clearances (air
space) to combustibles when passing through
ceilings, walls, roofs, enclosures, attic rafters,
etc. Do not pack air spaces with insulation.
Also note maximum vertical rise of the vent-
ing system and any maximum horizontal
offset limitations. Offsets must fall within the
parameters shown in Figure 25.
2. Set the fireplace in desired location. Drop a
plumb line down from the ceiling to the posi-
tion of the fireplace exit flue. Mark the center
point where the vent will penetrate the ceiling.
Drill a small locating hole at this point.
Drop a plumb line from the inside of the roof
to the locating hole in the ceiling. Mark the
center point where the vent will penetrate the
roof. Drill a small locating hole at this point.
Flat Ceiling Installation
1. Cut a 12 1 /
2
" square hole in the ceiling using
the locating hole as a center point. The open-
ing should be framed to 12 1 /
2
"x12 1 /
2
" inside
dimensions, as shown in Figure 18 on page
13 using framing lumber the same size as the
ceiling joists. If the area above the ceiling is
an insulated ceiling or an attic, nail firestop
from the top side. This prevents loose insula-
tion from falling into the required clearance
space. If the area above the ceiling is a living
space, install firestop below the framed hole.
The firestop should be installed with no less
than three nails per side (see Figure 26).
2. Assemble the desired lengths of pipe and
elbows necessary to reach from the fireplace
flue up through the firestop. All connections
must be sealed with high temperature silicone
sealant as specified in the second warning
statement on page 11. Be sure all pipe and
elbow connections are fully twist-locked (see
Figure 17, page 13).
3. Cut a hole in the roof using the locating hole
as a center point. (Cover any exposed open
vent pipes before cutting hole in roof.) The
12 1 /
2
" x 12 1 /
2
" hole must be measured on
the horizontal; actual length may be larger
depending on the pitch of the roof. There
must be a 1" clearance from the vent pipe to
combustible materials. Frame the opening as
shown in Figure 18 on page 13.
4. Connect a section of pipe and extend up
through the hole. If an offset is needed to avoid
obstructions, you must support the vent pipe
every 3 feet. Use wall straps for this purpose
(see Figure 24, page 15). Whenever possible,
use 45° elbows instead of 90° elbows. The 45°
elbow offers less restriction to the flow of the
flue gases and intake air.
X
12
Roof Pitch is
x 1 Listed
Clearance
8'
Minimum
Listed
Vent Cap
Lowest
Discharge
Opening
Listed
Gas
Vent
H (Min.) Height from Roof
Figure 25 - Vertical Vent Termination
Clearance
ROOF PITCH H(Min.)
Flat to 6/1 1.0'
6/1 to 7/1 1.5'
Over 7/1 to 8/1 1.5'
Over 8/1 to 9/1 .0'
Over 9/1 to 10/1 .5'
Over 10/1 to 11/1 3.5'
Over 11/1 to 1/1 4.0'
Over 1/1 to 14/1 5.0'
Over 14/1 to 16/1 6.0'
Over 16/1 to 18/1 7.0'
Over 18/1 to 0/1 7.5'
Over 0/1 to 1/1 8.0'