Monessen Hearth MDV500, MDV600 Installation & Operating Instructions Manual page 24

MDV Series Direct Vent Gas Fireplace
Figure 33 -
If area above is a room, install firestop above framed
hole as shown
4 x 6B\,
9
Venting
5 x 8
1 0
FP1969
Venting
firestop w room above
Nails
Figure 34 -
If area above is not a room, install firestop below
framed hole as shown
note: If an offset is needed to avoid obstructions, you
must support the vent pipe every three (3) feet. Use wall
straps for this purpose. Page 23, Figure 32. 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.
5. Place the flashing over the pipe section(s) extending
through the roof. Secure the base of the flashing to
the roof and framing with roofing nails. Be sure roofing
material overlaps the top edge of the flashing. There
must be a 1" clearance from the vent pipe to combustible
materials.
6. Continue to add pipe sections until the height of the
vent cap meets the minimum requirements as shown
in Figure 35.
note: You must increase vent height for steep roof
pitches. Nearby trees, adjoining roof lines, steep pitched
roofs, and other similar factors may cause poor draft or
down-drafting in high winds. Increasing the vent height
may solve this problem.
24
Nails
FP1969
Firestop
9
"
"
1 0
"
"
Firestop
FP1970
firestop no room
NOTE: If the vent pipe passes through any occupied areas
above the first floor, including storage spaces and closets,
you must enclose pipe. You may frame and sheetrock the
enclosure with standard construction material. Make sure
to meet the minimum allowable clearances to combustibles.
Do not fill any of the required clearance spaces with
insulation.
2 ft.
Min.
Termination
Vent
Storm
Collar
Flashing
Concentric
Vent Pipe
FP1970
VentIng InstallatIon
Horizontal Overhang
2 ft. Min.
Lowest
Discharge
Opening
H*
1" Minimum Clearance to
Combustibles
Figure 35 -
Minimum Chimney Clearance
roof pitch h (feet)
Flat to 6/12
Over 6/12 to 7/12 FP1971
Min chimney clearance
Over 7/12 to 8/12
Over 8/12 to 9/12
Over 9/12 to 10/12
Over 10/12 to 11/12
Over 11/12 to 12/12
*H - Minimum height from roof to
lowest discharge opening of vent
12
X
FP1971
1.0
1.25
1.5
2.0
2.5
3.25
4.0
75D2523