Can two fireplaces on different floors share one chase with separate vent pipes?
Yes — two fireplaces can rise through the same framed chase as long as each has its own dedicated vent pipe running full-length with the required clearance. Direct-vent and B-vent systems are engineered one-appliance-per-vent: you can stack the chases and share the enclosure, but you never tie two fireplaces into a single flue.
One vent per fireplace — always
Yes, two fireplaces on different floors can rise through the same chase, but each one gets its own dedicated, full-length vent pipe. The ironclad rule is one appliance per vent: you never tie two fireplaces into a single flue. Sharing a flue invites cross-drafting and combustion spillage, where one unit's exhaust gets pulled toward the other. Direct-vent and B-vent systems are listed and tested as one-appliance-per-vent for exactly that reason.
Sizing the shared chase
A shared chase just has to be built big enough to carry both pipes with each one's required clearance to combustibles maintained — they can't be crammed against each other or the framing. Up on the roof, the two terminations need proper spacing from each other and from anything else up there. It's very common in a two-story WNC home to stack a great-room fireplace below and a primary-bedroom fireplace above in the same chase, each venting independently.
Getting it right during the build
The time to nail this down is at framing, when the chase can be sized and the two vent paths laid out before drywall goes up. We coordinate with your builder so the chase fits both systems, the clearances hold, and the terminations land where code and the manuals want them. One licensed company owns the whole stack — fireboxes, vents, gas lines, permit, and inspection. Call (828) 545-0525.
How we can help
Related questions
- Can two fireplaces share one vent or chimney flue?
- Can direct-vent pipe be enclosed inside a wall or framed chase?
- What is a chase and does my fireplace need one?
- Can fireplace vent pipe be run up through the attic?
- How high above the roof does a chimney or vent pipe have to extend?
- Can I put a gas fireplace in my bedroom?
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