A direct vent gas fireplace on a wall under a cathedral ceiling has one vent path: straight up, through the roof. There is no attic to run pipe through and no ceiling plane to hide an offset above. The manuals cover this; the trouble is that they cover it in a procedure written for a flat ceiling and an attic, and the parts list is spread over several pages. This guide pulls it together for three Napoleon lines. Every figure and part number below is from the installation manual for that exact model: W415-2000 (revision L-0, 09.29.25) for the Elevation X, W415-2034 (revision D-0, 01.29.26) for the Vector, and W415-4121 (revision E-0, 01.29.26) for the Tall Linear Vector. Where a manual does not publish something, it says so below.
Why a Cathedral Ceiling Changes the Install
Napoleon's vertical installation procedure assumes three separate things: an opening in the ceiling, an attic above it, and an opening in the roof. The Elevation X manual's first three steps are to cut and frame a square opening "in the ceiling and the roof," secure the vent pipe shield plate over the ceiling opening, and then, "In the attic, slide the vent pipe collar down to cover up the open end of the shield and tighten. This will prevent any materials, such as insulation, from filling up the 1" (25mm) air space around the pipe." (W415-2000, page 25.)
Under a cathedral ceiling the ceiling and the roof are one assembly. The pipe passes through a single framed opening in a rafter bay, with the roof insulation packed on both sides of it, and comes out on a sloped roof. Four things follow:
- The vent path is fixed by the rafter bay. The pipe has to pass between rafters with 1" of clearance to combustibles all around on a vertical run (all three manuals). Which bay it uses decides where the fireplace enclosure sits, or how many elbows it takes to get there.
- Insulation has to be kept out of the air space. The framed opening, the firestop at its bottom and the shield above it are what keep the roof insulation off the pipe through the full depth of the rafters.
- The terminal sits on a pitch. The roof terminal kit is chosen by roof pitch, and the terminal has to be plumb on a sloped roof.
- Every offset costs run allowance. Napoleon's charts count elbows; two 45° elbows count as one 90° (W415-2034, page 22). A jog to reach the right rafter bay is measured against the same 40 ft total as the straight pipe.
The rest of this guide is the parts and the numbers that turn those four points into a framing plan.
The Firestop Rule
All three manuals print the same sentence: "A firestop must be placed on the bottom of each framed opening in a roof or ceiling that the venting system passes through." (W415-2000, page 25; W415-2034, page 33; W415-4121, page 35.)
"Each framed opening" is the operative phrase. On a cathedral ceiling install, count them: the roof/ceiling assembly is one, and if the fireplace enclosure has a framed top below the ceiling, that is another. Each gets a firestop at its bottom face.
The parts differ by whether the vent is flexible or rigid, and by model:
| Opening | Elevation X (W415-2000) | Vector (W415-2034) | Tall Vector (W415-4121) |
|---|---|---|---|
| Ceiling or roof, Napoleon flex vent | W500-0028, not supplied (page 25) | W500-0028, not supplied (page 33) | W500-0028, not supplied (page 35) |
| Ceiling or roof, rigid vent | 5DFS, not supplied (page 25) | Wolf Steel firestop or the vent manufacturer's firestop, to the manual's clearances (page 33) | 5DFS, not supplied (page 35) |
| Wall (horizontal termination only) | W010-4479, not supplied (page 24) | Wall firestop spacer W615-10007332, supplied with the unit (page 33) | Wall firestop spacer W615-10007332, supplied with the unit (page 35) |
Two points from that table. The Elevation X ships with no firestop of either kind; on a straight vertical run the W500-0028 is the one you need, and it is a line on the vent order. And the Vector and Tall Vector manuals both say to install the firestop before framing. The Tall Vector manual: "Before framing a see-through appliance, ensure to install the firestop first as it will not fit between the studs if installed after framing," with the same instruction for the single-sided unit (W415-4121, page 31); the Vector manual gives the same instruction on its rough framing page (W415-2034, page 30). Our see-through framing guide covers that sequence.
The Parts Nobody Accounts For
The fireplace crate contains no venting. Here is what the manuals require for a vertical run, and which of it is easy to miss.
The roof terminal kit, and what is in it
Napoleon names the kit by roof pitch: GD410 for 1/12 to 7/12, GD411 for 8/12 to 12/12, GD412 for a flat roof (W415-2000, page 13; W415-2034, page 15; W415-4121, page 15). The vertical installation steps then call for an air terminal connector attached to a roof support, flashing slid under the shingles, the terminal itself secured with "a minimum of three screws" for 5"/8" venting, and a storm collar bedded in "a heavy bead of weatherproof caulking 2" (51mm) above the flashing" (W415-2000, page 27; the same steps appear in W415-2034, page 35, and W415-4121, page 37).
What the manuals do not print is a packing list for the kit, so we are not going to tell you the storm collar is in the box. The roof support is described as optional (W415-2000, page 27). Before the roofer is scheduled, confirm the contents of the kit you ordered against that list: terminal, connector, flashing, storm collar. The caulking is not supplied.
Pipe supports every 3 ft
"The vent system must be supported every 3' (0.9m) for both vertical and horizontal runs." (W415-2000, page 13; W415-2034, page 34, and W415-4121, page 36, say "approximately every 3 feet.") The manuals accept "support ring assembly W010-0067 or equivalent non-combustible strapping." On a 20 ft vertical run inside a chase that is at least six support points, and they need framing to attach to. Metal strapping is a building-supply item; put it on the framer's list.
Coupler kits
Napoleon's flex vent comes as a 5 ft kit (GD420) or a 10 ft kit (GD430) (all three manuals). A 20 ft run is two 10 ft kits, and two kits have to be joined. The Elevation X manual's vent connection drawings show an inner coupler and an outer coupler at that joint (W415-2000, page 26) and do not list them as part of a vent kit. The coupler kit is its own line, and it is the line that goes missing from vent quotes.
The vent pipe shield plate
Where the vent passes through a finished ceiling, the manual has you caulk and secure "the Wolf Steel vent pipe shield plate or equivalent" over the opening (W415-2000, page 25). On a cathedral ceiling that is the finished face of the roof assembly, in the room.
Sealant, two kinds
The exhaust connection at the appliance flue collar "must be sealed using the black high temperature sealant Mill Pac," Napoleon part W573-0007; other joints take red RTV silicone, W573-0002. Both are listed as not supplied (W415-2000, pages 14 and 25–26; W415-2034, page 31; W415-4121, pages 14–15).
Elevation X only: the insulation sleeve
"The first 3 feet (0.9m) of outer 8" (203mm) diameter vent pipe from the appliance must be wrapped in the 1" (25mm) thick insulation sleeve (supplied)." (W415-2000, page 13.) It ships in the crate; it still has to go on.
The terminal height and the restrictor
All three manuals set the terminal at the same height: the top of the air terminal must be 16" above the highest point where it penetrates the roof (W415-2000, page 27; W415-2034, page 35; W415-4121, page 37). And on the Elevation X the vent restrictor plate is set according to the length of the run; section 4.3.4 of W415-2000 tables the setting for 8, 10, 20, 30 and 40 ft runs. A 20 ft cathedral run has its own setting.
Run Limits, by Model
These are the limits for a vertical (roof) termination, from each model's own manual. The minimum vertical rise is the figure that changes between lines.
| Model | Minimum vertical | Maximum vertical | Maximum horizontal | Total V + H | Source |
|---|---|---|---|---|---|
| Elevation X EX36 / EX42, natural gas and propane | 3 ft | 40 ft | 20 ft | 40 ft | W415-2000, typical venting installation (page 15) and all-terminations chart (page 17) |
| Vector LV38 / LV50 / LV62 / LV74, natural gas, single-sided and see-through | 6 ft | 40 ft | 20 ft | 40 ft | W415-2034, vertical termination (natural gas), page 22 |
| Vector, propane | 6 ft | 40 ft | 10 ft (LV38); 4 3/8 ft (LV50, LV62, LV74) | 40 ft | W415-2034, propane charts, pages 23–25 |
| Tall Vector TLV50 / TLV62 / TLV74, natural gas | 6 ft | 40 ft | 20 ft | 40 ft | W415-4121, vertical termination (natural gas), page 22 |
| Tall Vector, propane (after conversion) | Same limits on the propane charts (pages 23–24); the manual requires rigid venting for propane (page 23) | W415-4121 | |||
Read the Vector and Tall Vector minimum with its own caveat, printed under the chart: "A 6' (1.83m) minimum vertical rise is considered the minimum practical dimension for the specific appliance enclosure and a minimal building structure. However, a greater minimum vertical rise may be needed to suit the specific application constraints or local codes and / or regulatory requirements." (W415-2034, page 22; W415-4121, page 22.) Both charts also carry the note "V + H ≤ 40 ft. (For longer vent runs, a power vent is required)."
The Elevation X manual has one chart, "all terminations," with no separate propane chart; the Vector has separate natural gas and propane charts, and on propane the horizontal allowance drops to 4 3/8 ft on the 50, 62 and 74, with some short-rise configurations marked vertical termination only. If you are on propane, plan from the propane pages.
The minimum rise before a horizontal (wall) termination is a different figure again, and it also differs by model: 24" on the Elevation X, 30" on the single-sided Vector, 22" on the single-sided Tall Vector, with higher figures for the 62 and 74 see-through models. Those are on each product page. On a cathedral ceiling install they only matter if the vent turns; on a straight run, the vertical column above is the one to plan from.
Roof Pitch Matters
The terminal kit is pitch-specific, and the pitch of a cathedral ceiling is the pitch of the roof above it. GD410 covers 1/12 to 7/12; GD411 covers 8/12 to 12/12; GD412 is for a flat roof. Napoleon's listed kits stop at 12/12; a steeper roof is a question for us before anything is ordered, not a substitution on site. Measure the pitch, or read it off the drawings, before the vent is quoted, because the wrong kit is the wrong flashing.
Whatever the pitch, the terminal ends up 16" above the high side of the penetration, and the Elevation X manual adds that the air terminal "must remain unobstructed at all times" and be examined at least once a year (W415-2000, page 14).
What to Do Before Framing
Both linear manuals open their framing pages with the same instruction: determine the vent requirements before deciding the final location of the appliance. On a cathedral ceiling the vent path decides the chase, and a chase is cheap to draw and expensive to move.
- Pick the rafter bay. The pipe needs 1" all around on a vertical run. Locate the enclosure under a bay the pipe can pass through plumb, or count the elbows the offset will take and check the run against the chart.
- Size the enclosure to the model. Elevation X: 39 3/4" × 44 1/4" × 22 1/4" (EX36) or 45 3/4" × 48 1/4" × 22 1/4" (EX42), with a minimum enclosure height of 72" for a flush finish or 84" recessed (W415-2000, pages 21 and 36–37). Vector: 53 13/16" to 89 13/16" wide by 20 1/8" deep single-sided, 16 3/16" see-through; minimum enclosure height 73" (LV38, LV50) or 91" (LV62, LV74) from the bottom of the unit (W415-2034, page 30). Tall Vector: 65 13/16" to 89 13/16" wide by 48 3/16" high by 20 1/8" deep; 73" (TLV50) or 91" (TLV62, TLV74) (W415-4121, page 31). Both linear manuals add that the enclosure height "may be higher depending on venting configuration."
- Set the firestop before the framing goes up on a Vector or Tall Vector (W415-2034, page 30; W415-4121, page 31), and frame the roof/ceiling opening with its firestop at the bottom and 1" clear all around.
- Decide the heat management kit now. Dynamic Heat Control changes the framing above the unit because it needs an air outlet opening in the enclosure; on the Elevation X it is also the finishing-kit decision that has to be made "early on" (W415-2000, page 35). Our TV above a gas fireplace guide covers the clearances.
- Order the vent as a list, not a word. Two flex kits, the coupler kit, the pitch-matched terminal kit, the W500-0028 firestop, Mill Pac. Strapping, red RTV, caulking and non-combustible board are the contractor's.
- Run the services. All three lines are hardwired; the gas line and the 120 V supply go to the firebox location before drywall.
Napoleon's warranty terms state the gas appliance must be installed by a licensed, authorized service technician or contractor (owner's manual W415-2001, warranty page); coverage on all three lines is the Napoleon President's Lifetime Limited Warranty. American Hearth Supply supplies the equipment and quotes the complete build. The installation, including the vent, is your licensed installer's, working from the manual for your exact model.
Related Guides
- What a direct vent gas fireplace actually costs to install: the complete build, priced, with the vent package itemized
- Direct vent gas fireplace buying guide
- Tall Vector vs. Vector: framing and venting figures side by side
- See-through gas fireplaces: what to know before you frame
- Elevation X vs. Vector
Send Us the Section Drawing
Ceiling height at the fireplace wall, roof pitch, where the rafters fall, the model you are considering and the fuel. We will send back the vent parts list for that run, checked against the manual, with the complete build priced. Tell us what you're building or call or text (814) 440-4817.
Sources. Napoleon Elevation X installation manual W415-2000, revision L-0, 09.29.25: venting components, kits, support spacing and insulation sleeve page 13; sealant and terminal inspection page 14; typical venting installation page 15; all-terminations chart page 17; framing page 21; wall firestop page 24; ceiling firestop and vertical installation pages 25–27; restrictor section 4.3.4; finishing kit page 35; enclosure heights pages 36–37. Napoleon Vector installation manual W415-2034, revision D-0, 01.29.26: kits page 15; vertical termination chart page 22; propane charts pages 23–25; framing and firestop-first page 30; sealant page 31; firestops page 33; support page 34; vertical air terminal installation page 35. Napoleon Tall Linear Vector installation manual W415-4121, revision E-0, 01.29.26: kits and sealant pages 14–15; vertical termination chart page 22; propane pages 23–24; framing and firestop-first page 31; firestop rule and firestops page 35; support page 36; vertical air terminal installation page 37. Napoleon Elevation X owner's manual W415-2001, warranty page. American Hearth Supply is an authorized Napoleon dealer and supplies equipment only.
