Ceiling heat shield for Jotul 602

[Ditchmonkey]

Ditchmonkey: Would you kindly share the outcome with your ceiling-clearance reduction issue?

I went ahead and installed a ceiling heat shield with specifications I made up since I didn't have any. It does have one inch of clearance behind it. I was pretty sure the county inspector was going to reject it due to the issues revealed in this discussion, however he did grant the permit. I was lucky to get a flexible inspector.

The shop I bought the wood stove from is a complete circus, I don't know how they stay in business. In addition to selling me a stove with the wrong ceiling clearance, they refused to come out to advise me on a small issue I was having. If I were to do this again I would just order a stove direct like I did last time with Woodstock.

 

[begreen]

78" is a low ceiling. Is this in a room or an alcove? Sometimes a ceiling heat shield will echo the hearth protection requirement of 8" past the stove dimensions with an open 1" air gap behind it. Also specify the non-combustible material the heat shield would be made of and how the 1" gap would be maintained. It would be worth asking the town engineer if this would be permissible.

 

[BigVee]

Thanks for sharing your thoughts about having ceiling panel mimic the same dimensions of the steel hearth plate; I was thinking that would be reasonable approach in absence of any guidelines from NFPA. Yes, it’s a low ceiling in a c.1760 house. The new stove replaces an existing Vermont Castings stove (Resolute) that has been there for at least 30 years, and new stove will be in the exact location as the old stove, adjacent to the chimney. Using 1/2” Durock cement board, with 1” ceramic spacers to create air space, screwed into rafters, leaving the panel open on three sides for ventilation. Was further thinking that *also* replacing the affected area of existing ceiling (combustible) material with a 24 gauge stainless sheet, to which the spacers and cement board would be attached, would provide even more safety — i.e., a “sandwich” of cement board, over ventilated air space, over sheet metal. But that treatment is not among the options on the NFPA list, so not sure I should do?

 

[begreen]

The shield probably does not need to be 16" in front of the stove. That is for the strong radiation from the front of the stove and ember protection. I would think + 8" all around would be sufficient. I can't say whether adding the metal to the ceiling might make the reviewing engineer happier. It could be presented in the form of option A (no metal added) and option B (with metal). The metal could be plain or painted sheet metal. There's no benefit in using stainless for this application.

 

[BigVee]

Thank you, @begreen! Your insights very helpful here! Appreciate your time and attention.

 

[BCLoco]

Ok that chart gives you the reduction granted for various methods to that 96" requirement. So ceiling shields are allowed. To figure out the size you measure diagonally from the edge of the stove untill you meet the required clearance. Anything under that needs shielded.

This is the second place I've heard/read that method of determining ceiling heat shield size. Can you or anyone point to where that is specified in writing? I'm not trying to be contrary here, just genuinely interested in seeing where that comes from.

I'm having the same issues with low ceiling heights and lack of specs on ceiling heat shield sizing. Other than shield clearance from combustibles, it seems to be something you make up as you go and hope the inspector likes it.

The diagonal method quickly results in a very large heat shield. In our case, a small stove with a 24" x 24" footprint that calls for ceiling height of 84", means a heat shield of almost 8' square in our 72" (to bottom of upstairs floor joist timbers) log home ceilings.

 

[bholler]

This is the second place I've heard/read that method of determining ceiling heat shield size. Can you or anyone point to where that is specified in writing? I'm not trying to be contrary here, just genuinely interested in seeing where that comes from.

I'm having the same issues with low ceiling heights and lack of specs on ceiling heat shield sizing. Other than shield clearance from combustibles, it seems to be something you make up as you go and hope the inspector likes it.

The diagonal method quickly results in a very large heat shield. In our case, a small stove with a 24" x 24" footprint that calls for ceiling height of 84", means a heat shield of almost 8' square in our 72" (to bottom of upstairs floor joist timbers) log home ceilings.

Allot of what we are discussing here is US code. So it may not be applicable. But if your stove is listed the only one that can answer your questions is the stove manufacturer

 

[BCLoco]

Allot of what we are discussing here is US code. So it may not be applicable. But if your stove is listed the only one that can answer your questions is the stove manufacturer

Oh for sure I get that the codes have some differences, and anyone doing an installation should only be working from their relevant code book. But for conversation purposes, they're nearly identical. CSA B365 is basically a plagiarized version of NFPA 211, converted to metric.

As far as my questions, I only had one: Can you point to where that diagonal measurement method is specified in writing?

 

[bholler]

Oh for sure I get that the codes have some differences, and anyone doing an installation should only be working from their relevant code book. But for conversation purposes, they're nearly identical. CSA B365 is basically a plagiarized version of NFPA 211, converted to metric.

As far as my questions, I only had one: Can you point to where that diagonal measurement method is specified in writing?

Yeah I know they are really similar. But there are some differences here and there. I don't know Canadian code well enough to give them though

 

[BCLoco]

Yeah I know they are really similar. But there are some differences here and there. I don't know Canadian code well enough to give them though

I never said anything about Canadian code. I'm asking where the diagonal measurement method is written as an accepted method of determining ceiling shield size.

If you said it, you must have read it somewhere?

 

[bholler]

I never said anything about Canadian code. I'm asking where the diagonal measurement method is written as an accepted method of determining ceiling shield size.

If you said it, you must have read it somewhere?

Anything within the stated clearance requirements needs shielded. Radiant heat travels in all directions not just 90 degrees off of the stove.

 

[BCLoco]

Anything within the stated clearance requirements needs shielded. Radiant heat travels in all directions not just 90 degrees off of the stove.

You are going to great lengths to avoid answering my question.

I'm simply asking one single question: Where is the diagonal method described and written?

 

[bholler]

You are going to great lengths to avoid answering my question.

I'm simply asking one single question: Where is the diagonal method described and written?

Nfpa 211 and any stove manual that describes shielding

 

[Newbie78]

I was rather surprised that even though my distance from back wall to double wall stovepipe exceeds the minimum by several inches, the wall was getting pretty hot to touch directly behind the pipe. I used the side of an old electric range that we replaced as a heat shield. It is white enamel at this point. We may or may not re-paint it. It's a way nicer piece of tin than what you would buy as a "factory" heat shield, imo.. anyway, my point is that good tin for heat shields can be found in many places...

I saved the stove insulation blanket for dirt-bike silencer packing too. It's exactly the same product as the wee tiny package of insulation sold at the bike shop.

too much good stuff ends up buried in the landfill..

 

[BCLoco]

Nfpa 211 and any stove manual that describes shielding

Oh so it is in 211? You could have said that earlier, but we got there eventually. Thank you for your help.

I don't believe manuals for other stoves will help because they're not necessarily directly applicable. But a method described in another standards organization's manual will often be taken into consideration by inspectors where the standard-having-jurisdiction does not address the situation specifically. So even though NFPA 211 does not apply in my jurisdiction, I can use it to point to established precedent if the same is not directly addressed in CSA B365.

The reason this matters is because in addition to the massive heat shield that severely impedes head room in an already low ceiling room, it means having to move my listed stove much further from the wall than the manual calls for. Not because of concerns about the wall, but if you follow the diagonal method of measuring outward from every top edge, then obviously your stove has to be far enough away from walls or obstacles to allow for the enormous ceiling heat shield to be properly centered above it.

So, I need to get a copy of B365 and search it for low ceiling height directives. If none, then I will proceed with the 211 method, since it is relevant established precedent where none currently exists.

 

[bholler]

Oh so it is in 211? You could have said that earlier, but we got there eventually. Thank you for your help.

I don't believe manuals for other stoves will help because they're not necessarily directly applicable. But a method described in another standards organization's manual will often be taken into consideration by inspectors where the standard-having-jurisdiction does not address the situation specifically. So even though NFPA 211 does not apply in my jurisdiction, I can use it to point to established precedent if the same is not directly addressed in CSA B365.

The reason this matters is because in addition to the massive heat shield that severely impedes head room in an already low ceiling room, it means having to move my listed stove much further from the wall than the manual calls for. Not because of concerns about the wall, but if you follow the diagonal method of measuring outward from every top edge, then obviously your stove has to be far enough away from walls or obstacles to allow for the enormous ceiling heat shield to be properly centered above it.

So, I need to get a copy of B365 and search it for low ceiling height directives. If none, then I will proceed with the 211 method, since it is relevant established precedent where none currently exists.

Since it's a listed stove none of this matters at all. You need to follow the specifications in the manual. If it doesn't give you a way to reduce required ceiling height you can't do it. The nfpa clearances reductions etc only apply to unlisted stoves.

Call the stove manufacturer that is the only thing you can do.

 

[BCLoco]

Since it's a listed stove none of this matters at all. You need to follow the specifications in the manual. If it doesn't give you a way to reduce required ceiling height you can't do it. The nfpa clearances reductions etc only apply to unlisted stoves.

Call the stove manufacturer that is the only thing you can do.

That is utterly and completely false. Clearance reduction methods apply to any stated clearance specification.

Where did you get that nonsense?

And no, the lack of specific clearance reduction dimensions in the manual does not mean they are not allowed. Totally ridiculous statement to make.

Any manufacturer can simply put in a boilerplate statement like the one in my stove's manual:

"...Installation with reduced clearances must
comply with standard NFPA211 or CAN/CSA-B365."

 

[bholler]

That is utterly and completely false. Clearance reduction methods apply to any stated clearance specification.

Where did you get that nonsense?

And no, the lack of specific clearance reduction dimensions in the manual does not mean they are not allowed. Totally ridiculous statement to make.

Any manufacturer can simply put in a boilerplate statement like the one in my stove's manual:

"...Installation with reduced clearances must
comply with standard NFPA211 or CAN/CSA-B365."

Any manufacturer can put that in the manual but most don't because they are already reducing with ventilated radiant heat shields. I have not read your manual if it says that great.

And nfpa 211 clearly stated that data is for unlisted stoves. For listed stoves refer to manufacturers specs. Again none of this applies to you though you need to find out what applies in Canada.

Have you read all applicable codes for you? Have you talked to jotul? It seems you havnt read any of it but are calling me a liar because I am not simply telling you what you want to hear.

 

[BCLoco]

Any manufacturer can put that in the manual but most don't because they are already reducing with ventilated radiant heat shields. I have not read your manual if it says that great.

And nfpa 211 clearly stated that data is for unlisted stoves. For listed stoves refer to manufacturers specs. Again none of this applies to you though you need to find out what applies in Canada.

Have you read all applicable codes for you? Have you talked to jotul? It seems you havnt read any of it but are calling me a liar because I am not simply telling you what you want to hear.

The very first line of NFPA 211 12.6.2:

"12.6.2.1 Clearances from listed and unlisted solid fuel-burning appliances to combustible material shall be permitted to be reduced if the combustible material is protected as described in Table 12.6.2.1 and in Figure 12.6.2.1(a) through Figure 12.6.2.1(f)."

The clearance reduction table lists percentages that dimensions can be reduced by, depending on shield construction, and this is entirely independent of whether a stove is listed or not. Unless the manufacturer specifically states, in the manual or otherwise, not to reduce a dimension, then the clearance guidelines and accompanying clearance reduction table apply. It's physics, not witchcraft.

I've read plenty enough to know that you are stating things as facts which simply aren't. I never outright called you a liar, but you've made several statements which are obviously wrong and untrue. Whether that is from ignorance or lying is not for me to decide from here.

So now I'm realizing that I should go back to my question. You described the diagonal clearance method to someone in this thread as acceptable method of determining shield size, and now you've told me that it can be found in NFPA 211. Is that a fact? Can you quote the section?

 

[bholler]

The very first line of NFPA 211 12.6.2:

"12.6.2.1 Clearances from listed and unlisted solid fuel-burning appliances to combustible material shall be permitted to be reduced if the combustible material is protected as described in Table 12.6.2.1 and in Figure 12.6.2.1(a) through Figure 12.6.2.1(f)."

The clearance reduction table lists percentages that dimensions can be reduced by, depending on shield construction, and this is entirely independent of whether a stove is listed or not. Unless the manufacturer specifically states, in the manual or otherwise, not to reduce a dimension, then the clearance guidelines and accompanying clearance reduction table apply. It's physics, not witchcraft.

I've read plenty enough to know that you are stating things as facts which simply aren't. I never outright called you a liar, but you've made several statements which are obviously wrong and untrue. Whether that is from ignorance or lying is not for me to decide from here.

So now I'm realizing that I should go back to my question. You described the diagonal clearance method to someone in this thread as acceptable method of determining shield size, and now you've told me that it can be found in NFPA 211. Is that a fact? Can you quote the section?

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What version of nfpa 211 is that from. Obviously I am wrong according to that one but I was pretty sure they dropped the listed part from that statement due to the large number of manufacturers over riding that statement and not allowing further reduction. I will pull up a current version at some point today. If that listed statement is still there clearly I am wrong and apologize. And I know there is a diagram showing diagonal measurement in there somewhere for sizing. I will find it.

Regardless your safest option is to contact jotul and ask them directly. They are the ones that did the testing.

 

[Newbie78]

Liability is far different than common sense and real safety.

manufacturers of anything have been known to make grave mistakes.... It's even more common nowadays with too many lawyers and accountants calling the shots.

with what little I know at this point about boxes of fire and their accoutrements, I will err to the conservative side because things get way, way hotter than I imagined with 24/7 hot fires (thus my electric range-side heat shield behind the stove pipe even when the published specs are far exceeded). A wee fire for a few hours, or even continuously is nearly nothing in comparison.