Planning hearth for new century stove, is my construction plan correct?

[tlhfirelion]

I bought a century stove (model # FW240007) and am planning my hearth pad and walls for this "alcove" the stove will be halfway in. After reading the owners manual and the hearth pad articles on here, I do have a few questions to make sure I am doing this correctly.

The old fireplace and drywall is ripped out. There is a wooden box currently that I figure I should rip out and redo with metal studs correct?

My manual says that I need a pad that is at least 3/8th" millboard and non combustible. I am going to have cement board, the morter and then 2" thick concrete hearth stones so that is more than enough correct? Under the cement board is the plywood subfloor and then floor joists. Since this stove is on a pedistal I think I am ok there correct?

With regard to my walls that surround the stove, with the proper clearances for my stove and the following construction am I ok?
1) Metal studs
2) Cement board (2 sheets thick)
3) Metal lath
4) Scratch coat of morter
5) Cement stone veneer that is about 1.5 to 2 inches thick.

A) Behind this is the plywood box chimney that will(?) have fiberglass insulation a few feet up all the way around this new hearth pad and walls.

B) I have an 8" single wall pipe currently that I plan to line with a 6" stainless steel liner. 6" flue is what my stove manf. requires.

So am I headed in the right direction here or making any major mistakes or doing any unsafe construction? Thank you.

 

[Michael6268]

You will have more than enough for that stove. I have that stove and when its cranking at 600+ the hearth doesnt even get that warm. It does throw quite a bit of heat into the house though, for such a small stove. When I bought mine two years ago, it stated you only needed a "ceramic tile surface or equivialant". I have two sheets of cement board thickness an slate tiles on top of that. Sounds like your doing good.

 

[tlhfirelion]

great thanks. good to hear that it is a good stove. the price could not be beat. when we build a house I'll get a bigger and better stove.

Do you have the blower for this? We don't have it yet but heard we can get it at lowes or home depot come fall so plan to get that. Thank you for your reply.

 

[fossil]

Got that stove in my workshop, and I like it just fine. To put the blower on, you're gonna need about 5" or so behind the rear heat shield, and you'll have to move the stove to install it, unless you can get down there behind it, so if you plan to get it, I'd suggest you get it now and put it on the stove before you put the stove in place (even though it's just a pup, it's dang heavy!). I've seen them (the blowers) on eBay. The part number should be shown in your stove owner's manual. Good luck with it, it's a nice little stove. Rick

EDIT: I don't have the blower on my stove, don't need it in my little shop...I do have a small ceiling fan in there, it really does the trick.

 

[Michael6268]

We didnt get the blower. We burn mainly coal, but bought this stove to get our moneys worth out of the wood I collect. I have used this stove to heat a 1700 sqft area with no problem without a blower. Im sure the blower wouldnt hurt but you probably would not need it. The only negative I would say about this stove is due to the small size its hard to fit wood in sometimes if the coals havent burned way down and its hard to get an overnight burn sometimes. 6 hrs seems ok 8 is pushing it.

 

[tlhfirelion]

Got that stove in my workshop, and I like it just fine. To put the blower on, you're gonna need about 5" or so behind the rear heat shield, and you'll have to move the stove to install it, unless you can get down there behind it, so if you plan to get it, I'd suggest you get it now and put it on the stove before you put the stove in place (even though it's just a pup, it's dang heavy!). I've seen them (the blowers) on eBay. The part number should be shown in your stove owner's manual. Good luck with it, it's a nice little stove. Rick

EDIT: I don't have the blower on my stove, don't need it in my little shop...I do have a small ceiling fan in there, it really does the trick.

I have a nice sized ceiling fan in our living room where this stove is going so maybe I'll see how it does with that first before getting the blower. You do make a good point about getting the blower now......I'll have to think about that one. Thank you for your reply.

 

[tlhfirelion]

We didnt get the blower. We burn mainly coal, but bought this stove to get our moneys worth out of the wood I collect. I have used this stove to heat a 1700 sqft area with no problem without a blower. Im sure the blower wouldnt hurt but you probably would not need it. The only negative I would say about this stove is due to the small size its hard to fit wood in sometimes if the coals havent burned way down and its hard to get an overnight burn sometimes. 6 hrs seems ok 8 is pushing it.

Thats a valid point on the overnight burn, and one thing I have thought of. The price I got on this stove, and this is not our permanent home, it will do ok for now. Besides I am up at 5 before my wife but she goes to bed at midnight long after I'm asleep so the 6 hour burn time will actually work out fine I think. I'm about to start splitting some logs I have that are a year old so I can cut stuff into smaller lengths to accomidate this stove. Thanks for the reply.

 

[tlhfirelion]

anyone else care to comment on if my construction plan is ok for my situation? I want to make sure I am safe here.

 

[begreen]

Your plan sounds like overkill, but there is no issue with that. The clearances listed for the stove are to combustible surfaces. It sounds like in every way you will be exceeding the minimum requirements. No problem there, if you change the stove at some point, and it has stiffer requirements, you may be all set.

 

[tlhfirelion]

So if the correct clearances are maintained with the above construction, would I be ok to use wood studs to make the frame?

 

[fossil]

So if the correct clearances are maintained with the above construction, would I be ok to use wood studs to make the frame?

If you're talking about the "studs" being the framework on the floor beneath your hearth platform, it looks like you'd be OK going with wood. The stove manufacturer requires floor protection beneath the stove with an an R-value of 0.466. USG says that Durock has an R-value of 0.26 (I'm assuming they're talking about 1/2" material), so two layers of Durock will provide you with 0.52, then your stone some additional protection. I'm not a professional, so don't take my word for it...check with an expert to make sure you're building a safe installation. Rick

 

[tlhfirelion]

So if the correct clearances are maintained with the above construction, would I be ok to use wood studs to make the frame?

If you're talking about the "studs" being the framework on the floor beneath your hearth platform, it looks like you'd be OK going with wood. The stove manufacturer requires floor protection beneath the stove with an an R-value of 0.466. USG says that Durock has an R-value of 0.26 (I'm assuming they're talking about 1/2" material), so two layers of Durock will provide you with 0.52, then your stone some additional protection. I'm not a professional, so don't take my word for it...check with an expert to make sure you're building a safe installation. Rick

I should of clarified. I am talking about the studs that will create the box to attach the cement board too to then hang the stone on to create the hearth itself not the hearth pad. I hope to create a square alcove of sorts to then half the stove halfway in and halfway out of. I think that with the proper clearances and stone, morter, metal lath, and 2 cement layers of cement board, the frame that supports this would be ok to be wood.

 

[begreen]

You could have raw studs on the alcove walls as long as the clearances to combustibles are honored. If the stove has the side shields then there is a clearance reduction. Since this is being constructed from scratch, if you can, add a couple inches to all clearances for greater peace of mind. There are no penalties for exceeding minimal guidelines. If side and back clearances are generous, then I would only use a single layer of durock on the walls. It's often doubled up on the hearth pad for additional stiffness and strength if the hearth pad has gaps between the framing members.

Will this alcove have a ceiling? If yes, attention needs to be paid to the clearance requirements over the stove as well.

 

[fossil]

...I should of clarified. I am talking about the studs that will create the box to attach the cement board too to then hang the stone on to create the hearth itself not the hearth pad. I hope to create a square alcove of sorts to then half the stove halfway in and halfway out of. I think that with the proper clearances and stone, morter, metal lath, and 2 cement layers of cement board, the frame that supports this would be ok to be wood.

If your goal is to reduce the manufacturer's minimum required clearances from combustibles on the sides and rear of the stove, then you'll have to design and build the hearth walls with an integral ventilated 1" air space. Just affixing masonry (or Durock) directly to wood or drywall doesn't do much for you...the clearance still has to be measured from the stove to the combustible material. Incorporating a 1" ventilated air space into the wall construction will allow you to reduce the clearances somewhat (can't remember the exact amount allowed, you'll need to research that and make sure you're doing this safely). If your stove's gonna be halfway in, it sounds like you're really building a hearth stove setup. You'll need to be concerned with what's above the portion of the stove that's sitting inside the opening. The book may have instructions pertaining to an "alcove" installation that may help guide you. I recommend you get some expert advice...which is not something I'm able to provide. Rick

 

[tlhfirelion]

You could have raw studs on the alcove walls as long as the clearances to combustibles are honored. If the stove has the side shields then there is a clearance reduction. Since this is being constructed from scratch, if you can, add a couple inches to all clearances for greater peace of mind. There are no penalties for exceeding minimal guidelines. If side and back clearances are generous, then I would only use a single layer of durock on the walls. It's often doubled up on the hearth pad for additional stiffness and strength if the hearth pad has gaps between the framing members.

Will this alcove have a ceiling? If yes, attention needs to be paid to the clearance requirements over the stove as well.

I do plan on building this alcove with the clearance specs taken into consideration. So if I honor the clearances and have the above mentioned materials with wooden studs as the frame, I think I'll be ok. I was thinking about making the "roof" of the alcove angle upwards towards the mantel to kind of direct heat out of the alcove. However I'm not sure if I will then be dealing with issues with my mantel since it is wood. While I don't mind going overboard on the guidelines I do have a limit on the space I can use. I don't want a hearth that covers 200 sq. ft. lol

I would like to use wood not just because I have plenty to use already, the metal studs are new to me and am not sure
I want to mess with a new technique along with all this other stuff. This whole project is a learning process for me so maybe
I will. who knows. thank you for your reply.

 

[tlhfirelion]

...I should of clarified. I am talking about the studs that will create the box to attach the cement board too to then hang the stone on to create the hearth itself not the hearth pad. I hope to create a square alcove of sorts to then half the stove halfway in and halfway out of. I think that with the proper clearances and stone, morter, metal lath, and 2 cement layers of cement board, the frame that supports this would be ok to be wood.

If your goal is to reduce the manufacturer's minimum required clearances from combustibles on the sides and rear of the stove, then you'll have to design and build the hearth walls with an integral ventilated 1" air space. Just affixing masonry (or Durock) directly to wood or drywall doesn't do much for you...the clearance still has to be measured from the stove to the combustible material. Incorporating a 1" ventilated air space into the wall construction will allow you to reduce the clearances somewhat (can't remember the exact amount allowed, you'll need to research that and make sure you're doing this safely). If your stove's gonna be halfway in, it sounds like you're really building a hearth stove setup. You'll need to be concerned with what's above the portion of the stove that's sitting inside the opening. The book may have instructions pertaining to an "alcove" installation that may help guide you. I recommend you get some expert advice...which is not something I'm able to provide. Rick

I don't plan on trying to reduce the clearances that the manufacturer dictates and yes this is in an alcove. When you say "The book" what do you mean exactly? you mean the 4 pieces of paper that came with my stove? lol

 

[fossil]

...When you say "The book" what do you mean exactly? you mean the 4 pieces of paper that came with my stove? lol

Yup. Same four pieces of paper that came with mine, no doubt. Rick

 

[tlhfirelion]

...When you say "The book" what do you mean exactly? you mean the 4 pieces of paper that came with my stove? lol

Yup. Same four pieces of paper that came with mine, no doubt. Rick

Yeah, I figured I would get a bit more info but I guess not. The only way to contact CFM (who makes my century stove) is to snail mail them or call them in canada. I'm going to try and cll them on monday and see if I can speak with someone who can answer my questions about an alcove design and this stove, but I am expecting to come up empty handed. Wish me luck.

 

[BrotherBart]

Actually the manual for that stove is 14 pages and available here:

http://www.cfmcustomercare.com/elements/uploads/files/Manual_FW240007_EN.pdf

 

[fossil]

Right. The four pieces of paper that came with my stove contain all the salient information in that file, including the clearance diagrams and pertinent data, printed two sides and folded, sans the maple leaf and some boilerplate. Rick

 

[BrotherBart]

You have a steel stove. Nobody that cares how their home looks burns wood in those things. Therefore they don't need instructions either. It's just a square barrel. after all. :lol:

 

[fossil]

You have a steel stove. Nobody that cares how their home looks burns wood in those things. Therefore they don't need instructions either. It's just a square barrel. after all. :lol:

Yer right, BB. All I need to know is where the loading door is, and I'm good to go. Rick