Monessen Hearth Direct Vent Gas Fireplace MDV500 - Manual (Page 26)

26 75D2523
10
1 /
2 " 10
1 / 2
"
VENT INSTALLATION
INSTALLATION FOR VERTICAL TERMINATION
1. Determine the route your vertical venting will take. If ceiling joist,
roof rafters or other framing will obstruct the venting system,
consider an offset. See Figure 33 to avoid cutting load bearing
members.
NOTE: Pay special attention to these installation 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 venting system and any
maximum horizontal offset limitations. Offsets must fall
within the parameters shown in Figure 14, page 17.
2. Set fireplace in desired location. Drop a line plumb down from
the ceiling to the position of the flue exit. Mark the center point
where the vent will penetrate the ceiling. Drill a small locating
hole a this point.
Drop a plumb line from the inside of the roof to the ceiling locat-
ing 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 10
1 /
2
" (267mm) square hole in the ceiling using the locat-
ing hole as a center point The opening should be framed to
10
1 /
2
"x10 1 /
2
" (267mm x 267mm) inside dimensions as shown in
Figure 34 using framing lumber the same size as the ceiling joist.
If the area above the ceiling is an insulated ceiling or a room,
nail firestop from the top side. This prevents loose insulation
from falling into the required clearance space. See Figure 34.
Otherwise, install firestop below the framed hole. The firestop
should be installed with no less than three nails per side. See
Figure 35.
2. Assemble the desired lengths of pipe and elbows necessary to
reach from the burner system flue up through the firestop. Be sure
pipe and elbow connections are fully twist-locked. See Figure
16, page 18.
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 10
1 /
2
"x10 1/2 " (267mm x 267mm) hole must be measured on
the horizontal. Actual length may be larger depending on the pitch
of the roof. There must be a 1" minimum clearance from the vent
pipe to combustible materials. (Insulation should be considered
a combustible material) Frame the opening as shown in Figure
17 on page 18.
4. Connect a section of pipe and extend up through the hole.
Figure 33 - Offset with Wall Strap and 45°
Elbows
Roof
Flashing
Wall
Strap
45° Elbows
Ceiling Firstop
Figure 34 - If area above is a room, install
firestop above framed hole as shown
Figure 35 - If area above is not a room, install
firestop below framed hole as shown
Continued on next page
Firestop
Nails
Nails Firestop