Alcove installation: in-wall ventilation

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New Member
Sep 13, 2023
I just removed a zero clearance fireplace and I'd like to install a Morso 2B Classic stove in the alcove. I have 38" of space between combustible studs. The framing itself has ventilation on the subfloor (down into basement crawlspace that has outside air coming in) on both sides and on top it's open into the attic which vents to the outside through the roof peak. The chimney would be completely replaced and exit the alcove vertically up to the roof.

I would use steel studs to frame in a slightly smaller enclosure and cover with 1/2" durock and tile.
With this stove the distance to combustibles would be 12" on each side.

Can I use the existing airflow to ventilate behind the barrier and comply with 211?

Alcove installation: in-wall ventilation
Unfortunately, Morso's docs are a bit spartan. There are no clearance reduction options or alcove clearance requirements listed in the manual. I think this is in part because it was written for universal English covering many countries besides the US.

If the walls are set up per NSPF 211 wall shielding requirements and the closest clearance is 12", then it should be safe, but that doesn't mean approved. Before proceeding with this stove, get written approval from the inspecting authority and the insurance company. You'll likely need to show drawings of the proposed shielding method, ceiling clearance, stove distances, hearth design, etc. for submittal.