Replacing ZC fireplace with alcove freestanding - Layout, clearances and other issues

[jstluise]

After discovering I have a contractor grade ZC fireplace (class A chimney), my project wasn't going to be as simple as putting in an insert. I posted about this before and my options are to install a ZC insert ($$$) or tear everything out and do an alcove freestanding stove. I want to get this project rolling and opted for the alcove with the freestanding.

The house 1250 sq ft and I am baselining the Englander 13NC because the price is right and it seems a lot of people are happy with it. I live in western Washington (King County). I think the 13NC will be a good fit for our house/climate. As of right now I'm hoping for an end result similar to this (pulled from google image search): http://i.imgur.com/DxLFN5s.jpg

Finally got around to taking some measurements and making a layout to see what kind of clearances I can get with where the current flue is. I'm not reusing the old chimney, but it would be nice if I can go straight up with the new chimney. Here is my current layout with the 13NC drawn in:



I checked with WA state codes for clearances and it said to refer to the manufactures clearances. From the 13NC manual, here are the required clearances and some other info:



My drawing does not show any of the wall protection (just shows the structure framing), so that will add another 4"-5" (I'm guessing). It looks like I am okay for the sides, even without heat shields; however, the back is too tight once I consider the wall protection. And, if I want to use the blower I will need a bit more room. Looks like I'll have to move the stove out about 10" and end up having a jog in the chimney as it goes up through the attic. Not the end of the world. Any thoughts on the layout? There is the note about the 8" behind for the floor protector, but I think that is assuming no wall protection...otherwise the clearances in the table don't make sense.

I got to looking at the King County requirements and stumbled across a note about the combustion air supply:



Reading this I was thinking I need an outside air supply, but because the stove is certified for WA state, it makes me think the stove passes the "Negative Pressure Test" that is noted at the bottom and that I don't need an outside air supply. Pretty sure, since the duct on the stove is 3" and the note calls for 4" anyways.

I think that is it for now. Still doing research and I plan on stopping in at a local wood stove shop to see what they think as well. I'd love to get some input from the forum, though.

Oh, other things I found out is that a mechanical permit will cost me about $200 and that my homeowner's insurance has a ~$40/yr surcharge for free-standing wood stoves (no surcharge for inserts)!

Thanks!

 

[Grisu]

First, very nice hearth that you plan on building. I hope we get to see pictures once it is done.

Regarding the clearances: I think that part in the 13NC manual is a bit misleading. What you have to go with are the clearances given in the table. The 2nd paragraph talks about the possibility that some jurisdictions will require NFPA 211 clearances (36") regardless. Only then can you reduce the wall clearances with appropriate heat shields down to 12". I don't think it was meant that you can reduce clearances from the table any further. Please give Englander's customer service a call before starting your project. You can then also inquire about the need for an outside air kit. Even if it is not required by code, it will help with draft and be more energy efficient. May not be a bad idea to put one in regardless of the code. You will also need install a floor protection with a r-value of 2 if there are any combustibles underneath. One of the biggest disadvantages of the 13NC, IMHO. (Btw. I don't think you will find the 13NC in a local stove shop. It is usually sold by large retailers like Home Depot etc.)

How wide is the alcove overall? And is the center of the current pipe 10" from the backwall?

Is the stove supposed to become your primary heat? The firebox is a bit small for an overnight burn. As I recall, most users talk about burn times of 6 hrs. If you want to keep it going 24/7 and not wake up to a cold house a slightly larger stove with a firebox >2.0 cu ft would be more appropriate.

 

[jstluise]

First, very nice hearth that you plan on building. I hope we get to see pictures once it is done.

Regarding the clearances: I think that part in the 13NC manual is a bit misleading. What you have to go with are the clearances given in the table. The 2nd paragraph talks about the possibility that some jurisdictions will require NFPA 211 clearances (36") regardless. Only then can you reduce the wall clearances with appropriate heat shields down to 12". I don't think it was meant that you can reduce clearances from the table any further. Please give Englander's customer service a call before starting your project. You can then also inquire about the need for an outside air kit. Even if it is not required by code, it will help with draft and be more energy efficient. May not be a bad idea to put one in regardless of the code. You will also need install a floor protection with a r-value of 2 if there are any combustibles underneath. One of the biggest disadvantages of the 13NC, IMHO. (Btw. I don't think you will find the 13NC in a local stove shop. It is usually sold by large retailers like Home Depot etc.)

How wide is the alcove overall? And is the center of the current pipe 10" from the backwall?

Is the stove supposed to become your primary heat? The firebox is a bit small for an overnight burn. As I recall, most users talk about burn times of 6 hrs. If you want to keep it going 24/7 and not wake up to a cold house a slightly larger stove with a firebox >2.0 cu ft would be more appropriate.

Thanks for the reply. I will definitely post up some pictures before/during/after.

I understand what you are saying about the clearances. The wording definitely can be better and it is a bit confusing how they threw that comment in there about the 36" , but I believe I interpreted it correctly in my first post. The table shows minimum clearances between the stove and combustible walls, but if the walls are non-combustible (i.e. an approved wall board with 1" space between board and wall), then the clearances in the table can be reduced by 2/3. The way I interpret the comment about the 36" is if my area requires the 36" clearances, that overrules everything and the tables in the manual are no longer valid. I will definitely call Englander and ask; that was also one of my goals of visiting a local stove shop. Also, for the sake of clarity, the "heat shields" noted in the table refer to the optional heat shield you can add on to the stove, not the wall protection.

As for the outside air kit: if I am not required to have it (another thing to ask Englander and a local shop), I'm not sure if I will use it or not. I've read some of the debates online and like anything else there are people on both sides.

The width of the alcove (from stud to stud) is 53" as noted in the drawing. And yes, the center of the current pipe is 10" from the front of the back-wall stud. I was able to take all these measurements from the attic and the crawlspace below. Here is my current fireplace:



This stove will be for supplemental heat; otherwise I have a gas furnace. My plan is just to use it in the evenings during the week once we get home from work. During the cold months we have the furnace hold the house at 55ish when we are gone. It will be nice to let it burn into the night but I don't expect it to hold until morning. It might be nice to have something a bit bigger, but I'm not sure I have the room for it (e.g. the 30NC). I'm also open to other suggestions on a stove. I know a local stove shop won't carry Englander, but I will see what they offer as well as get some advice regarding the other issues I brought up. Also, I want to see what they say about installing the chimney; I'm comfortable with doing all the work except the chimney...figured having a pro come in and do that would be a good move.

 

[bholler]

but I believe I interpreted it correctly in my first post. The table shows minimum clearances between the stove and combustible walls, but if the walls are non-combustible (i.e. an approved wall board with 1" space between board and wall), then the clearances in the table can be reduced by 2/3

Not necessarily true many stove makers will not let you use heat shields to reduce clearances beyond what they have tested. You really need to check with englaner on this. And a wall with a heat shield is not noncombustible at all if it truly was non combustible then you could put the stove as close as you want but it is not.

 

[jstluise]

Not necessarily true many stove makers will not let you use heat shields to reduce clearances beyond what they have tested. You really need to check with englaner on this. And a wall with a heat shield is not noncombustible at all if it truly was non combustible then you could put the stove as close as you want but it is not.

You're right, non-combustible was the wrong word obviously. I'll give Englander a call and get to the bottom of this.

 

[Grisu]

Take a look at the Jotul F45. Clearances can be reduced pretty significantly with heat shields in an alcove. And its flue outlet is pretty far in the rear; maybe you won't even need an offset. It is also slightly larger than the 13NC so overnight burns would be possible if you ever want or need to go that route.

If I remember corectly the Napoleon 1400 has also pretty close clearances but I am not sure if it is EPA II-approved. Maybe worth looking into regardless.

 

[aansorge]

See if you can find a good deal on a Lopi as they have excellent clearances and are sturdy little suckers.

 

[jstluise]

I just got off the phone with Englader to get a clarification on the clearances. The 2/3 reduction does in fact refer to numbers in the table, just like I mentioned in my first post. So, you can get very close with approved wall protection (see the red numbers I put in the table). I asked about the 36" clearance and it said it is very rare to have a code that requires NFPA 211 clearances; most areas just say to refer to the stove installation manual (including my area). He couldn't comment on outside air kit...I'll have to check with a local stove shop on that.

So this is good news for me since my alcove is pretty small. Still exploring other stove options (thanks all for the recommendations!), but at least I have the 13NC to fall back on since I know it will fit.

Please see the response from @stoveguy2esw below for the correct information.

 

[bholler]

Ok good to know that many stove makers dont allow for further reduction

 

[begreen]

This is the first I have heard of this approved reduction for the 13NC. PM Mike Holton here (@stoveguy2esw) to verify those close clearances with the Englander. He works at Englander.

Here is a previous thread on the topic:
https://www.hearth.com/talk/threads...-the-englander-13nch-but.108494/#post-1423929

 

[jstluise]

PM Mike Holton here (@stoveguy2esw) to verify those close clearances with the Englander. He works at Englander. This is the first I have heard of this approved reduction for the 13NC.

Here is a previous thread on the topic:
https://www.hearth.com/talk/threads...-the-englander-13nch-but.108494/#post-1423929

Thanks! I'll definitely do that. Based on the post you linked to it sounds he'll say the minimum is 12" based on NFPA 211 and you can't get tighter than that. I'm not sure who I talked to at Englander, but we'll get to the bottom of this.

An appliance can be approved to be closer than the 12", just as he brought up ("Unless the appliance is specifically listed for lesser clearance..."). But maybe the Englander is not approved. The Jotul F45, for example, can get as close as 4" on the rear with protected walls.

I'll report back!

 

[Grisu]

I concur with BeGreen; that seems very unusual. Here is UL's take on wall shields:

Wall shields are placed over combustible wall-construction materials for the purpose of reducing the clearance to combustible materials from that required for individually
Listed appliances and equipment, except when the appliance or equipment listing specifically prohibits the reduction of clearances. The reduced wall clearances are specified as a
percentage in the individual Listings. Wall shields are not intended to reduce clearances to less than 12 inches or for reducing clearances when the clearance specified by the
appliance and/or chimney-connector Listing is 12 inches or less. However, clearances less than 12 inches are allowed when the specific appliance and chimney connector system has been tested and labeled together with a specific wall shield at the
clearances specified in the appliance’s installation instructions.

Source: (broken link removed to http://ul.com/wp-content/uploads/2014/04/UL_-Floor-Protectors1.pdf)

I interpret the bolded part that a manufacturer needs to test the stove together with a wall shield to determine if further reductions from the listed clearances are allowed. Simply using the generic reductions stated in NFPA 211 would not be permitted. That could be the difference between the 13NC and the F45 for example. Jotul may have tested the stove in a protected alcove.

 

[begreen]

Thanks! I'll definitely do that. Based on the post you linked to it sounds he'll say the minimum is 12" based on NFPA 211 and you can't get tighter than that. I'm not sure who I talked to at Englander, but we'll get to the bottom of this.

An appliance can be approved to be closer than the 12", just as he brought up ("Unless the appliance is specifically listed for lesser clearance..."). But maybe the Englander is not approved. The Jotul F45, for example, can get as close as 4" on the rear with protected walls.

I'll report back!

I'm seeing 7" for the F45 with protected walls. Also, be sure there is adequate clearance above the stove in the alcove.

 

[stoveguy2esw]

I checked with WA state codes for clearances and it said to refer to the manufactures clearances. From the 13NC manual, here are the required clearances and some other info:



My drawing does not show any of the wall protection (just shows the structure framing), so that will add another 4"-5" (I'm guessing). It looks like I am okay for the sides, even without heat shields; however, the back is too tight once I consider the wall protection. And, if I want to use the blower I will need a bit more room. Looks like I'll have to move the stove out about 10" and end up having a jog in the chimney as it goes up through the attic. Not the end of the world. Any thoughts on the layout? There is the note about the 8" behind for the floor protector, but I think that is assuming no wall protection...otherwise the clearances in the table don't make sense.

I got to looking at the King County requirements and stumbled across a note about the combustion air supply:


Reading this I was thinking I need an outside air supply, but because the stove is certified for WA state, it makes me think the stove passes the "Negative Pressure Test" that is noted at the bottom and that I don't need an outside air supply. Pretty sure, since the duct on the stove is 3" and the note calls for 4" anyways.

I think that is it for now. Still doing research and I plan on stopping in at a local wood stove shop to see what they think as well. I'd love to get some input from the forum, though.

Oh, other things I found out is that a mechanical permit will cost me about $200 and that my homeowner's insurance has a ~$40/yr surcharge for free-standing wood stoves (no surcharge for inserts)!

Thanks!

I see where this got confusing. Note in the paragraph from the 13-NC manual "In some areas local codes may require Thirty Six inches (36") from a combustible."

this is where a reduction per NFPA 211 with approved wall protection allows the 2/3 clearance. it does NOT allow that reduction from the "Listed" clearance in the manual.

my apologies for the incorrect information disseminated from one of my technicians, thanks to @begreen for suggesting contacting me directly.to the OP I hope this hasn't caused any issues with construction already started. please feel free to continue to contact me directly with any future questions you may have.

 

[jstluise]

I interpret the bolded part that a manufacturer needs to test the stove together with a wall shield to determine if further reductions from the listed clearances are allowed. Simply using the generic reductions stated in NFPA 211 would not be permitted. That could be the difference between the 13NC and the F45 for example. Jotul may have tested the stove in a protected alcove.

Thanks for the info. That all sounds right to me. Looking at the F45 manual it specifically says to follow NFPA 211 for wall protection, so they had to have tested their stove in a protected alcove.

I'm seeing 7" for the F45 with protected walls. Also, be sure there is adequate clearance above the stove in the alcove.

You're right, I was looking at the wrong diagram. My alove will be full height, so I'll have plenty of clearance above for whichever stove I choose.

Thanks, @stoveguy2esw for getting me the correct information. One question I do have is: do the clearances listed for the 13NC apply for alcove installs? I just noticed other manufacturers have different clearances for alcoves vs. corner installs. Luckily no construction has started yet...I'm still narrowing down which stove will work. I think the 13NC will still work (with stove heat shields), even without doing any wall protection. The rear clearance is a bit large, but I'd have to move it out anyways to make room for the blower.

 

[Grisu]

If you are looking for a budget stove that will work in your alcove, the Heatilator Eco-coice WS18 has a 9.5" side clearance in an alcove with double-wall pipe. (broken link removed) (page 30). Together with its 25" width you should still have enough room for a nice wall finish. Rear clearance is 7". It is not quite as cheap as the 13NC but also not in the price category of the F45.

 

[jstluise]

If you are looking for a budget stove that will work in your alcove, the Heatilator Eco-coice WS18 has a 9.5" side clearance in an alcove with double-wall pipe. (broken link removed) (page 30). Together with its 25" width you should still have enough room for a nice wall finish. Rear clearance is 7". It is not quite as cheap as the 13NC but also not in the price category of the F45.

Thanks for the recommendation. The WS18 looks to be a good candidate. It is a bit deeper than the 13NC, but it has a bigger firebox which is a plus. And with the reduced rear clearance it won't stick out much further than the 13NC.

I was playing around with my layout drawing and moved the 13NC out a bit to meet the clearances in the table (I put 13" to account for drywall/tile). With a double-wall and the heat shields installed on the 13NC, I will be able to meet the clearances without having any sort of wall protection. And my hearth will actually stick out the same distance that my fireplace does right now. With my alcove walls I could just drywall it or put up some nice tiles, which will be easier than putting up "wall protection" with the 1" spacing.



The configuration would look similar with the WS18, and I could even get away with having a single wall pipe with that stove. Regardless of which stove I choose, I think there will be an offset between the new and old stove pipe location.

Which leads me to my next question. If the stove manuals give all the guidelines for clearances BELOW the ceiling, what determines the clearances ABOVE the ceiling in the attic?

 

[begreen]

The class A chimney pipe is what sets the clearances above the ceiling support box. Most require 2" from the nearest combustible.

An advantage of the WS18 is easier hearth construction. It requires ember protection only. The 13NC has a stiff, R=2.0 hearth requirement. The other Englander that might be worth checking out is the Madison. It is a bit larger but with good clearances and ember only hearth protection. Sells for under $800. Another would be the Pacific Energy True North TN19 for about the same price.

(broken link removed to http://www.amfmenergy.com/50masmheup18.html)
(broken link removed to http://www.pacificenergy.net/products/wood/fireplaces-2/truenorth/)

 

[jstluise]

Great! Thanks for more recommendations. Yeah I saw the WS18 only calls for R = 0.13, which would make things easier.

 

[Grisu]

One thing I forgot: AFAIK, since you are in WA any stove needs to have less than 2.5 g/hr in emissions. (EPA-II standard) See here: http://www.ecy.wa.gov/programs/air/indoor_woodsmoke/wood_smoke_page.htm The WS-18 is just above that level at 2.6 g/hr and may therefore not be an option, unfortunately. When looking at different models check their emission specs.

 

[begreen]

It's ok. The 2.5 g/hr. limit is for catalytic stoves. Non-catalytics need to be less than 4.5 g/hr.

 

[jstluise]

The class A chimney pipe is what sets the clearances above the ceiling support box. Most require 2" from the nearest combustible.

An advantage of the WS18 is easier hearth construction. It requires ember protection only. The 13NC has a stiff, R=2.0 hearth requirement. The other Englander that might be worth checking out is the Madison. It is a bit larger but with good clearances and ember only hearth protection. Sells for under $800. Another would be the Pacific Energy True North TN19 for about the same price.

(broken link removed to http://www.amfmenergy.com/50masmheup18.html)
(broken link removed to http://www.pacificenergy.net/products/wood/fireplaces-2/truenorth/)

It looks like the Madison doesn't quite meet the clearances I need. The side clearances are 17.5" (single wall, side shields) which is a bit big for my space. They don't have values for the double wall connector...I guess it wasn't tested with that.

I'm liking the WS18 and TN19 over the 13NC...they have slightly larger fireboxes and the hearth constructions would be much easier. One thing with the TN19 is that the back clearance is pretty tight, so I'll probably be within a couple inches of the current location of the chimney...I might be able to do a straight shot for the chimney without any elbows.

I appreciate the help!