Gas Fireplace Combustible Requirements
A client removed their woodburning fireplace (metal unit with steel chase) and has installed a gas unit. The space is too large for the gas unit and they would like the opening narrowed on both sides to enclose the new unit.
I checked the 2003 IRC but couldn’t find any guidance on combustible clearance requirements for factory-built gas fireplces. I would need to add framing next to both sides of the unit and either install drywall or perhaps CBU to close off the gaps.
I have seen many of these units installed, often with oak mantels and surrounds enclosing them. Before I add anything combustible near it, however, I’d like to know the code requirements (if any) or any suggestions/recommendations you might have.
The photos are of the unit, the first as it stands now, the second with the old mantel placed in front of it. The mantel will be modified and reinstalled.
Thanks.
BTW, I haven’t seen the manual for this model, nor do I know the manufacturer. But I will prior to drafting the proposal.
“I am the master of my fate, I am the captain of my soul.” Invictus, by Henley.
Replies
Check the manufacturers recommendations/instructions. We use the IRC 2000 so I'm not going to look it up but most all model codes have the catch all phrase "per manufacturers reconditions" that applies to any appliance. In the houses I'm building right we are using a 36" gas direct vent fireplace that looks nearly identical to your pic. It is basically a zero clearence unit so I have them frame a hole that is 36 1/2w x 34 H. I'm raising the unit 6 1/4" by building a 2x6 platform with a piece of 3/4" floor sheathing on it - again which looks exactly like what you have. The fireplace surround I believe is the the code requirement you really want to know about. For economy reasons I'm using black slate - 6" legs and header piece and a 12" hearth. The wooden mantle overlaps the slate surround only by about 1/4". The 6" platform raise requires a second header piece which is also 6" and is installed below the face of the unit. Raising the unit puts the mantle up at a more esthetically pleasing height. Looking at your pic - it would almost look like you can reuse the mantle you have if you can get it off without tearing it up. Or at least the mantle is normally installed after the surround - being a remodeler you guys probably have all kinds of tricks for saving money and time while producing a reasonable result, so maybe you could lay marble tile (Isn't that what the hearth is?) inside the existing mantle to streamline the process.
As the other poster said, it really depends on the mfg/model. The QuadraVent I'm installing (see pic) requires 18" non-combustable above (and they stress that doesn't mean sheet rock of any kind). Because my unit is 16" off the floor it would put the mantle too high so I had to scratch it. The instructions are also very specific about how far something (even non-flamible) can protrude based on height above the unit.