Installation
900414-00 12/2015
Innovative Hearth Products
MHD 35/40 Series Direct-Vent Gas Fireplaces
24
Clearance to combustibles
Maintain the minimum clearance to combustibles (e.g., framing, attic, ceiling insulation, etc.).
For all vertical runs:
• 1” (26 mm) from all sides
NOTE: Attic insulation shield
(
H3907
, see
Page 45
)
must be installed when blown or loose-fill insulation is used,
and is required for all attic installations.
For all horizontal/inclined runs:
• 3” (77 mm) from the top
• 1” (26 mm) from the sides
• 1” (26 mm) from the bottom
11.
Install the Vent System
Items Unique to Mobile Homes
Remember to maintain 1 in. (26 mm) clearance to combustibles, framing members, and attic or ceiling insulation
when running vertical chimney sections. Attic insulation shield (H3907) may be used to obtain the required
clearances indicated here. See installation accessories table on
Pages 45 and 46
. The gap between the vent pipe
and a vertical firestop can be sealed with non-combustible caulking.
Install firestop thimble at the ceiling to roof location—Position appropriate firestop thimble at the bottom side of ceiling
and secure temporarily with two appropriate fasteners. Attach permanently, using at least two more fasteners, after vent
sections have been assembled through the firestop thimble and after any necessary adjustments have been made.
Ensure the thimble penetrates the roof opening. The thimble must extend completely through the ceiling or roof cavity
to the outermost plane of the roof. Use thimble extension SVTE26 when the distance between the outside of the roof
and the inside of the ceiling exceeds the height of the firestop thimble. The thimble provides for zero clearances to
combustibles and must be used at the ceiling/roof in manufactured homes with Secure Vent double wall vent sections.
Maintain 1 in. (26 mm) clearance between the thimble and the outer pipe of the secure vent chimney system. See
Figure
18
for pitched roofs or flat roofs with flat ceilings or
Figure 19
for pitched roofs with cathedral ceilings.
Figure 18 - Roof Penetration
Figure 19 - Roof Penetration
Note: Trim Thimble/
Extension To Desired Length
And Pitch At The Roof Line
14” Min.
Pitched Roof
Pitched Roof
Bow Roof
14” Min.
Outer Pipe Of
Chimney
Outer Pipe Of
Chimney
Outer Pipe Of
Chimney
14” Min.
Firestop
Thimble
Extension
13”
Firestop
Thimble
Firestop
Thimble
Thimble
SV-FSTFE
Install the Vertical Termination Vent System
These instructions should be used as a guideline and do not supersede local codes in any way. Install venting
according to local codes, these instructions, the current National Fuel Gas Code (ANSI-Z223.1) in the USA or the
current standards of CAN/CGA-B149.1 in Canada.
14” Min.
Outer Pipe Of
Chimney
Use correct firestop
thimble depending on the
pitch of the interior
ceiling.
Note: Regular Thimble
(SV-FSTFE) Can Be Used
If A Header Is Constructed
At This Point
