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Does anyone have details on building a fireplace with an indoor chimney that sits against a wall? I’m about to build a house with one that has the chimney just inside the exterior wall. In fact, the drawing shows it inside the wall. Every architectural detail and code book I’ve seen shows a 2″ clearance required between the masonry and any framing. Are there exceptions/techniques that allow contact or do I have to pull it forward at least 2″ into the room?
Thanks for your help,
Andrew
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I could be wrong but I believe the 2" clearance is to be maintained between the opening of the fireplace (where the fire burns) and any wood framing or trimwork. Otherwise, I believe your wall framing can go directly against any exterior brick of the chimney.
Of course, I am not certain as I've never built a fireplace. Maybe someone else here will pop in with more input.
Pete
*I do not know which code you follow, but the CABO says:1001.14 Chimney clearences. A portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum air space clearance to combustibles of 2 inches (51mm). Chimneys located entirely outside the exterior walls of the building, including chimneys that pass through the soffit or cornice, shall have aa minimum air space clearance of 1 inch (25mm). The air space shall not be filled, except to provide firestopping in accordance with section 1001.15.Section 1001.15 says to see section 602.7, which is the firestopping section. There is one exception to the air space, and that is if the chimney liner is listed in accordance with UL1777 and labled for use in contact with combustibles.So I guess the answer under CABO isthat you need the 2" unless you have a specially listed liner.Frank DuVal
*Thanks for the feedback guys. I read that passage in the code book, but somehow missed the part about listed liners. Most 'zero-clearance' liners I've found were re-liners for repairing cracked flues...I guess you could use one in new construction? I found reference to one new-work product that sounded like it might work and I'm waiting for a call back now. I also spoke with the county inspection agency who says no way around the 2" even with a liner, so I guess I can't use one without special approval. Basically, I have to allow the 2", then I can fill the gap with firecode drywall. Thanks again,Andrew
*Andrew, we follow CABO, and the 1"- 2" clearance applies to framing members. Trim and siding can touch the masonry. Just make sure the mason fills all the head joints in the blocks.Good Luck
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Does anyone have details on building a fireplace with an indoor chimney that sits against a wall? I'm about to build a house with one that has the chimney just inside the exterior wall. In fact, the drawing shows it inside the wall. Every architectural detail and code book I've seen shows a 2" clearance required between the masonry and any framing. Are there exceptions/techniques that allow contact or do I have to pull it forward at least 2" into the room?
Thanks for your help,
Andrew