Roof Exit vs Wall Exit Chimney Systems: Which One Is Right for Your Wood Stove?
When planning a wood stove installation, one of the most important decisions you'll make is how the chimney will exit your structure. You’ve got two main options: through the roof or out the wall. Each has its pros and cons, and the right choice depends on your setup, structure, and comfort level with the install.
In this guide, we’ll walk you through the tradeoffs, some key principles of chimney performance, and the most common reasons folks choose one over the other.
Roof Exit: Pros and Cons
A roof exit sends the chimney pipe straight up through the ceiling and out the roof. It’s the most direct route for flue gases and usually the best-performing option when it comes to stove draft.
Pros:
- Best draft performance: Hot air rises, and the straight-up path creates strong, reliable draft with fewer obstructions.
- Warmer starts: More of the chimney stays inside your space, so the flue heats up faster and starts drafting sooner.
- Lower cost: Roof exits use less Class A insulated pipe than wall exits, which keeps total cost down.
Ideal for mobile rigs: If you're installing in a van, RV, skoolie, or travel trailer, a roof exit helps avoid vulnerable exterior pipe runs and keeps your chimney more compact.
Cons:
- Ceiling obstructions: If you have a loft, ridge beam, ceiling fan, or other structural elements in the way, a roof exit might not be practical.
- You’ll have to cut into your roof: This makes some folks nervous, especially if their roofing material is tricky to seal (like membrane or metal seams).
- Limited roof pitch compatibility: Roof exits work best on roofs with at least a 10-degree slope. On flatter roofs, a wall exit may be a better fit.
If your space allows for it, a roof exit is often the simplest, most efficient way to vent your stove. The strong draft it creates can help your stove burn cleaner and start easier, especially in cold weather.
Wall Exit: Pros and Cons
A wall exit routes the chimney pipe horizontally through an exterior wall before turning upward outside your structure. It’s not as efficient as a roof exit, but it can be the better choice depending on your layout and preferences.
Pros:
- Routing flexibility: If your ceiling has a loft, solar panels, a second story, or major obstructions, a wall exit can help you avoid them.
- Avoids cutting into your roof: For some folks, going through the wall just feels more approachable.
- Exterior chimney aesthetics: Some people prefer the look of a pipe running up the outside wall instead of through the roof.
Compatible with flat roofs: Roof exits aren’t recommended on roofs with less than a 10-degree pitch. In that case, a wall exit may be your best option.
Cons:
- Weaker draft: The 90-degree turn and horizontal section slow down flue gases. You’ll usually need a taller chimney stack to compensate.
- Colder starts: More of your chimney is exposed to outdoor air, so it takes longer to warm up and start drafting well.
- Higher cost: Because it requires more Class A insulated pipe, a wall exit typically costs about 50% more than a roof exit in the same structure.
- Less flexibility in pipe lengths: Exterior chimney pipe comes in fixed lengths that can’t be cut to size like single-wall stove pipe can.
- Not ideal for mobile rigs: If you’re installing in a van, RV, or travel trailer, we don’t recommend a wall exit. Exterior pipes are more prone to damage while in motion and typically don’t allow for enough vertical rise.
With the right design and chimney height, a wall exit can still perform well. It just takes a bit more planning to make sure your stove drafts properly.
Flue Design Theory and Draft Performance
No matter which exit you choose, the goal is the same: help your stove draft well. That means smoke moves up and out efficiently, and your fire burns clean and strong.
Here’s what helps:
- Height matters: More height equals stronger draft. We recommend at least 60 inches of vertical pipe for roof exits and 80 inches for wall exits.
- Keep it hot: A warmer chimney drafts better. Try to keep as much pipe as possible inside the heated space.
- Limit turns and bends: Every elbow slows things down. If you need to offset, use 45-degree elbows instead of 90s where possible.
- Use the right pipe: Single-wall or double-wall stovepipe can be used indoors. Once the pipe goes through a wall or roof, switch to Class A chimney pipe.
- Match your flue size to the stove: Bigger is not always better. An oversized flue cools gases down and weakens the draft.
Learn more about the theory of flue design here.
Common Design Challenges
Choosing your chimney exit is just one piece of the puzzle. You’ll also want to think through:
- Offsetting pipe around framing or obstacles
- Understanding roof pitch and how it affects chimney components
- Working with fixed pipe lengths on wall exits
If you're not sure how to make it all fit, we’re happy to help.
Use Our Kit Builder Tool
Use our Kit Builder Tool to plan your system and generate a complete parts list tailored to your structure. Try it with both options to compare costs and components. Whether you're cutting into the roof or heading out the wall, we’ll help you get it done right.
Want to dig deeper? If you like seeing how the sausage is made, use this Roof Exit Planning Worksheet to plan a roof exit step by step. Wall exits are their own beast, so we created a separate Wall Exit Planning Guide for those who want the full breakdown.
See it in Action
Every project and installation has its own unique considerations. Walk with Nick through his thought process as he decides how to route the flue in this off-grid office installation.
Need Help?
If you're still weighing your options, talk to one of our team members. We’ve helped thousands of folks get their stove systems up and running safely and efficiently. Email us at support@tinywoodstove.com or call 208-352-3417.
You don't have to figure it all out on your own. We’re here to help.