Framing For Support Box

Fine folks, hi, this is the first of many more questions from me most likely ... I've read several moderator messages stating that there aren't any stupid questions so I hope I won't prove that point wrong! I've lurked a little while and read as much as I possibly can concerning wood stove installation, selection and utilization and I must say that this site is totally terrific.

I am installing our first wood stove ( I hope to post the whole adventure with pics a little later ) and I am wondering about the framing for the support box. The stove store's owner ( a Regency dealer who really seems super sharp ) has told me that the 12x12 support box can be framed by regular wood studs. Although I don't doubt him at all (again he seems super sharp and extremely experienced at this) I find myself fretting about putting regular studs right up against the support box. I'm wondering whether in even extreme situations that has proven problematic? I'm also wondering whether it would be beneficial to use steel studs or something even stronger than studs like square 16 -18 gauge steel tubing ( I can weld really well and custom creating a square steel frame for the support box would be super simple for me.

I sometimes have the tendency of overthinking things (especially with safety related stuff) and am likely letting that happen here too however now is the time to really think these things out and act accordingly. Any advice you all have would be appreciated and ultimately used. If it matters, the stove is getting installed into an alcove. Thanks in advance for any advice at all.

BeGreen said:

Welcome to the forums. As long as you use all the components of the flue/chimney from the same manufacturer's system, this is not an issue. You can use wood studs to attach the support box without concern. The support box is designed to maintain the proper2" safety clearances for both the connector pipe and for the class A high-temp chimney pipe it is supporting.

A couple tips for installation of the support box. 1) If this is in an existing ceiling, pre-drill the holes for attaching the 2x4 braces to the joists and screw rather than nail these braces in place. That will save possible damage to the sheetrock ceiling. When all has been installed, be sure the support box is completely cleaned of any sawdust or wood chips.

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Wow, thanks for the fast response and the advice! Along with your advice and the dealer's advice (which match like mirrors by the way!) I'm understanding more and more that using wood studs will still be safe and might make the install that much simpler; I was finding myself fretting about the thought of close-fitting-combustibles and I was just trying to imagine if steel studs would prevent a problem in an extreme event.

The ceiling to this alcove is all new and not existing at this time. I am basically converting from a factory built fireplace which was installed in a "chase" that went from the floor to the ceiling of our living room. I removed the fireplace, the flu and everything else up through the chimney cap. Then I converted the chase framing into alcove framing per code permits. Then I wrapped everything with Wonderboard. Now I'm tiling the alcove floor and alcove walls in preparation for the stove to be installed by the dealer then I'll finish the ceiling tiling and everything else for final finish. I'm trying to do everything extremely well and it has helped immensely to have such a superb dealer as well as this forum to ask advice from. If there is anything additional I should consider here please feel free to say so. Thanks Again!

Dakotas Dad said:

If you want to take a cruise through the pictures in my link, you may find some shots that help you out. be sure to take lots of pictures.

In an alcove type instal, things can be a bit different..

Is this existing chase you are working with brick? If you have done framing around where the stove will sit, did you take into account the clearance to combustibles requirements for your stove.. I sure hope so ;-)

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Hi and thanks for the response! I loved looking through that link; it looks like you really have a super setup!

The existing chase essentially is just Type X Sheetrock. I did take into account not only the clearance to combustibles but also the alcove height which according to our own regional inspector has to be the right height regardless (minimum of 84", mine will basically be 85") of whether the materials there are combustible or not. In other words the framing for the alcove is set at 86.75" (from the subfloor) and then with the .75" on bottom for backer board/ cement board (1/4" thick) and mortar and tile and then 1.0" on top for the backer board/ cement board (1/2" thick) and mortar and tile I will have 85 inches to the alcove ceiling. I am taking tons of photos to post a little later if anyone is interested in them. Again if there is anything else I should think through now, I'd love to learn it from you folks. Thanks Again.

BeGreen said:

Sounds like some good planning. Take pictures and post them here. And feel free to ask more questions as they come up. If we can't answer them, well at least we might entertain you.

PS: What stove is going in?

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Thanks for that! It is a Regency Alterra CS1200. I can't wait to use this stove; I'm going from an inefficient, dirty, dusty, usafe (due to the badly buckled inside wall of the triple wall chimney) factory-built-fireplace to an efficient, clean, comfortable, modern and safe wood stove. It should be sweet. Thanks Again.

Install fire 1 said:

That is a sweet little stove! Congrats.

What side panels are you going with? Red, black or SS?

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Thanks! We are going to go with the Stainless Steel as our overall decor is definitely towards the minimalist/modern side of spectrum. On the one hand we were wanting something slightly larger (like the CS2400) as our house has ~1600 sqft and we are in colder climate, but, the CS2400 is bigger by its depth mostly and not bigger by its width much. That pushed the stove's front face out of the alcove in an extremely awkward looking way so we stayed with the CS1200. We really won't know how much house this will heat however the house's design will definitely help as it is an extremely efficient almost completely open concept house with cathedral ceilings leading two all three levels. Additionally we have a huge ceiling fan centered in the room the stove will sit in and that will hopefully help pull the heat from the alcove and push it up the cathedral ceilings as much as possible into other areas around the house. We will see but anyway thanks again for the compliment. I'm wondering whether anyone else here has the CS1200 and what they think of it? Thanks Again.

Okay, I thought of another one (stupid question). I searched around some and tried to answer my question but I think I'm misunderstanding some basic stuff.

How much weight will my ceiling support box / chimney support box (what's the right technical term there?) actually support once it is installed?

I'm trying to get a grasp of how strong and sturdy the framing there should be. On the one hand I can simply screw a single set of 2x4's (or preferably 2x6's if they will work with the support box?) through the WonderBoard that is lining the interior of the chimney chase and then into the framing that is immediately behind the WonderBoard for the side-to-side connections and then screw a set of smaller 2x4's within that for the front-to-back connections. Or I can get crazy and frame a full support system with a bunch of bracing where I would be able to support some serious weight. I just don't know what's really required for a safe system.

When I removed the chimney for my fireplace I'd guess the whole thing was not much more than 50 pounds but I was surprised that all that weight was supported simply by the fireplace itself. I have no idea how triple-wall-air-insulated chimney compares in weight to double-wall-insulated Class A Chimney? I also have no idea where that weight is distributed. If it is also 50+ pounds and that support box supports all of that on its own, I'd think that something more that two 2x4's supporting that assembly would be wise? Again, I may be misunderstanding some basic stuff here so please don't be afraid to spell this out. Thanks.

BeGreen said:

The support box assembly can hold a lot of weight. The framing should be solid, but no need to overkill. 2 decking screws per 2x4 end are sufficient. But there's no harm using 2x6s if you are more comfortable with that. Or you could support the pipe using a tee bracket. This is the way to go if you are going to enclose and wall off the chase on the interior side and put a cleanout door on the exterior of the chase.

Download the installation manual for class A chimneys for more ideas. Simpson has a nice one.

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Wow that looks totally different than what I was imagining for a support box. I was imagining a square steel box with a round hole through the middle that connected directly to horizontal studs. Those look like they connect to the vertical wall studs. But, either which way I can clearly see that the support box still could conceivably hold up as much as the fireplace previously had held up so I'll strengthen it accordingly ( using 2x6's will allow three strong screws per side ). Compared to the previous chimney (12" OD triple wall air insulated ), is the new chimney (6" ID double wall insulated) heavier or lighter per linear foot? Thanks for the advice again. I really appreciate it.

Dakotas Dad said:

We used simpson dura plus. The instructions said that the support box would support 10 sections of triple wall chimney. That's 30 feet, about 250lbs. Ours is supporting 8 sections. At least with ours, and I can think of NO reason it's not the same for every brand, the ceiling support box is designed to provide the required distance from combustibles. I just used screws from the inside out.. three per side.

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Wow, 250 lbs ! That's a good amount of weight. 6" Class A Chimney seems much heavier per linear foot than the old 10" triple wall tubing I had. Still, this is still something that two studs should be able to support but I think that I'll add just another little bit of bracing with that in mind. I'll be supporting somewhere around 22 feet if my calculations are correct so a little bit less than 250 lbs. This is helpful information, thanks for the advice.

mikeyd said:

Turbo - I'm also looking for some "Real life" reviews of the 1200 or specifically the 2400. They definitely have a different look to them that your traditional looking stove and seem to be a lot more powerful than similiar looking units from Morso, etc. We just installed a BIS NOVA in a small prefab last winter (it's all that would fit) and I'm looking for something else to compliment the other side of the building for some bedrooms, etc. The CS2400 might do the trick but am also looking at a Napoleon 1400 or 1900 or PE unit. The CS2400 is relatively new from what I understand from my reading - does anyone out there have some direct experience ? I think it's basically the same firebox as the F2400 but in a more modern looking exterior - thoughts from anyone ?

thanks!

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mikeyd, when I was in research/selection mode, I was basically toggling between Regency's S2400, CS2400 and CS1200. As soon as I first heard about the addition of the CS2400 to Regency's line, I knew I wanted it, but, I was also weary of getting first year for production of an all new stove setup. I actually called and talked to an engineer at Regency and he explained that although the CS2400 was just recently released, it is indeed the same firebox that they use in their other "2400" models (the F2400 as well as S2400). You should therefore expect the same sort of performance and reliability out of the CS400. We still want the CS2400 as we know for a fact that it is large enough (we're truthfully not totally sure the CS1200 will be large enough) but unfortunately with where we have to have the stove the CS2400 stuck out so far into the room and so far past the existing chase, it just didn't work well. In any case, yes it is indeed the same firebox as the other 2400's and it is the same sort of design otherwise for the side panels and back panels/frame/stand etc as the CS1200 which so far seems to be a really reliable workhorse from whatever I've read. I hope that helps answer things ... as I've already mentioned I'm not an expert at any of this but I think I had the same specific questions that you have here and was able to ask Regency directly so hopefully this is pretty sound stuff.

Dakotas Dad said:

We used simpson dura plus. The instructions said that the support box would support 10 sections of triple wall chimney. That's 30 feet, about 250lbs. Ours is supporting 8 sections. At least with ours, and I can think of NO reason it's not the same for every brand, the ceiling support box is designed to provide the required distance from combustibles. I just used screws from the inside out.. three per side.

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Sorry to ask two separate things from this post but, I'm still having a hard time visualizing the inside of the support box. When you say you screwed 3 screws from the inside out ... is the support box "open" inside or is it a tube within a box? If it is open, and you screw through the outside layer how does that prevent terrible fires? If it is really a tube within a box is that tube removable for installation purposes. I wish I had an example and I could answer all these things but if you don't mind helping me visualize this contraption I'd appreciate it. Thanks.