Which is the final call, the stove mfg. or the pipe mfg and NFPA211?

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begreen

begreen

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Nov 18, 2005
104,666
South Puget Sound, WA
My turn for a question. This one kept me up last night. I noted in another thread that a stove manual has a stove clearance that put the single-wall connector clearances under 18". I did some digging through stove manuals for stoves that have close clearances and a flue exit towards the rear of the stove. I found another example in the Quadrafire manuals. In the 3100 manual there is a single-wall pipe clearance of 12" for the steptop and 15.5" for the flat top. ???

So this begs the question of tested single-wall NFPA211 clearances vs the stove tested clearances. I haven't recently tested single-wall pipe at 12" from a wall with a 900°F degree flue, but I'm fairly certain that it will take the wall directly behind it to an excess of over 200°F if the pipe stays hot for an extended period of time. Now I know this is not recommended operation, but the design of the system is to be safe in spite of user foolishness. It seems to me that a stove manual (regardless of company) should have a footnote by clearances that are under the code clearances for the pipe that says *will require approved shielding of pipe to achieve these clearances.

This is the kind of thing that would have old Elky calling his legislators. Am I being pedantic, missing something, or are the stove mfgs. being coy here?
 
The tested clearances are really only for stoves which are not listed to specific clearances.
If a particular design tests out at closer than the NFPA standards, then that is an exception. There are many exceptions....in fact, most stoves are an exception in one way or another. I have seen some stoves listed to 42" instead of the generic 36". and some pipe had to be further than 18". The Resolute Acclaim may have been one...where the pipe was further than 18".

Remember Elk got tripped up by installing a Dutchwest to a NFPA clearance from the ceiling? The manual (testing) required more than the NFPA clearances.

In short, NFPA really means nothing or little to a listed stoves - the manual and label are the real deal.
 
The stove mfg has the final say they did the testing.
 
BeGreen,
You bring up an excellent point. If doing an install do you A, observe the stove builders requirements. B, the pipe manufacturers. Or C, accommodate both because if you do have a fire, I'm sure the suit dummy from the insurance company will be out to measure everything up after the smoke settles, and looking for that one reason to not pay you out. I think I would lean towards the pipe manufacturers requirements. They can build cars that do 160mph but the Man posts a limit and fines you in excess.
 
Daryl said:
The stove mfg has the final say they did the testing.
Click to expand...

Of the stove, but did they test the wall 24" above and behind the stove at 12" with single-wall pipe? I got readings of 150+ off the wall 12" away with double-wall pipe on the Castine after 24/7 burning. I'm pretty certain single-wall would have cooked the paper on the drywall. How is this considered safe?
 
They have black painted plywood walls with thermocouples inserted into them to mock up the walls......so, yes, they test the wall at the clearance that the manufacturers specifies. In fact, these days many tests are done at the manufacturers and witnessed by the test labs....I think they may be even working out virtual witnessing (data feeds, etc.)......

I think they have dozens of thermocouples at various locations, so all temps are logged.
 
The testing I saw they had themo couples on every thing they could walls,pipe,stove, floor.They go all out.
 
I'm a belt and suspenders kind of guy so I would not go with minimum clearance anyway. I would add an additional margin to the greater of the two. I've used metal studs, radiation shield, and concrete where combustibles were allowed. Better safe than sorry.

I've seen minimum numbers change over the years, probably in response to an "oh-sh!t, we thought it was good enough" revelation.
 
You should always build to the most restrictive standard.
In the end though, all that matters is whatever the Building Inspector or Fire Chief wants, no matter what the code or manual actually states.
 
I wouldn't be surprised if less than 50% of all stoves installed are inspected. That would be an interesting number to find out.

Personally I agree with exceeding the minimums, especially in the case of a stove posting close clearances with single-wall pipe. There are too many stoves heading out of big-box stores with owners preconceived notions of the hell with inspections. This seems like an area where folks could get in serious trouble, especially if they are pushing a small stove too hot.
 
Webmaster said:
They have black painted plywood walls with thermocouples inserted into them to mock up the walls......so, yes, they test the wall at the clearance that the manufacturers specifies. In fact, these days many tests are done at the manufacturers and witnessed by the test labs....I think they may be even working out virtual witnessing (data feeds, etc.)......

I think they have dozens of thermocouples at various locations, so all temps are logged.
Click to expand...

And yet docs are published with stoves like this. Confusing?
 

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BeGreen said:
I wouldn't be surprised if less than 50% of all stoves installed are inspected. That would be an interesting number to find out.

Personally I agree with exceeding the minimums, especially in the case of a stove posting close clearances with single-wall pipe. There are too many stoves heading out of big-box stores with owners preconceived notions of the hell with inspections. This seems like an area where folks could get in serious trouble, especially if they are pushing a small stove too hot.
Click to expand...


On the subject of inspections in Wisconsin most wood stove,chimney installs do not get inspected,only in new construction and areas that require a permit to put in a wood stove (which are few). I would say only 20 percent get inspected in our area. Most of our wood customers live in rural areas.
We take great pride in putting in a chimney and stove that meets or exceeds all specs. I have never seen any damage occure from following the mfg specs.
The NFPA211 is for non listed installs not for a listed appliance. But those guidelines are what the mfg must meet or exceed.
I ounce had a inspector hold up a job for a week because he did not believe that there was such a thing as a close clearance firestop for triple wall air cooled pipe that was a listed part in the manual. He had to eat crow on that call.
 
I can believe that. In most rural areas I would also guess less than 20%.

So in the case cited above which clearance would you follow, the repeated 18" clearance minimum for single-wall or the contradicting 13" distance in the stove table?
 
The chimney would be my first concern that would be placed out 18" from combustibles so single wall can be hooked up to any stove. If that cant happen Dbl wall stove pipe to the appliance.
 
Here in the county where we live, no inspection or permit is required. I happen to be buddies with the building inspector, and he was out for lunch yesterday, and looked at my on going install, all he said was I was building way beyond anything else he had seen anyone do, and if I burned my house down I would have to try perty darn hard. lol. He and his wife have heated with wood for 25 years. Gave me some good tips.

What I did CtC wise was exceed the stove manufacturers requirments for the stove and the pipe/chimney manufacturers requirments for those.. although the instructions for all three seemed to be the same CtC distances.
 
Daryl said:
The chimney would be my first concern that would be placed out 18" from combustibles so single wall can be hooked up to any stove. If that cant happen Dbl wall stove pipe to the appliance.
Click to expand...

'Nuf said. I like the way you plan :).
 
Not to get off topic, but what ever happened to Elk anyway?
 
BeGreen said:
Daryl said:
The chimney would be my first concern that would be placed out 18" from combustibles so single wall can be hooked up to any stove. If that cant happen Dbl wall stove pipe to the appliance.
Click to expand...

'Nuf said. I like the way you plan :).
Click to expand...

Yeah, I'm having a very difficult time resolving this in my mind. I've been all over the Internet, and everbody from the pipe manufactuers to the bell hops say 18" CTC for single wall. I think if I were doing a new installation, and I couldn't get someone from the stove manufacturer to convince me otherwise, I'd install to the most conservative/safe/restricted clearances. If I found an apparent discrepancy between stove & stovepipe requirements, I'd default to the more generous one. In this example, I'd keep my pipe at least 18", and let the stove fall where it may. Awaiting further clarification. Rick
 
elmoleaf said:
You should always build to the most restrictive standard.
In the end though, all that matters is whatever the Building Inspector or Fire Chief wants, no matter what the code or manual actually states.
Click to expand...
The codes are "minimum standards". "whatever the Building Inspector or Fire Chief wants".... if he is smart, what he wants will not have anything to do with it. The codes and standards are the result of testing. When those are modified by a manufacturer, they have tested (and are labled by the testing body as acceptable). I never think that I know more than the code or standard or UL listing. That would be be stupid.
 
What I don't understand is how the pipe mfg. testing and stated a clearance requirement gets trumped by a stove manufacturer that says, our results show different. Did the stove mfg. test with a chimney fire and the flue pipe at it's limits?

Safety standards are not " if you run this correctly". They are designed to protect property and lives when the unexpected happens. When really cold weather strikes, folks are pushing their systems, pedal to the metal hard. I want to be sure that the advice I give is based on worse case scenario.
 
tfdchief said:
...I never think that I know more than the code or standard or UL listing. That would be be stupid.
Click to expand...

Well, I'm not so sure that would be "stupid" in your case, chief...but that's another subject entirely. In any case, it seems to me that what we're talking about here is a consumer/installer/inspector/whoever being faced with a situation where there are two apparently contradictory requirements, both based on testing and certification. The stove manufacturer says you can place the stove such that single wall pipe is closer than 18" from combustibles, while the pipe manufacturer says you cannot. "Ay, there's the rub..." (Hamlet, Act III Scene i). Rick
 
If I found an apparent discrepancy between stove & stovepipe requirements, I'd default to the more generous one. In this example, I'd keep my pipe at least 18", and let the stove fall where it may. Awaiting further clarification. Rick
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As an inspector, I think that is the call I would make. Sometimes, even in the codes and standards and listings, things are overlooked. Unfortunately, that is where inspectors get a bad name sometimes because unfortunately, as the AHJ, they must interpret the code, and then have the final say. And some are better at that than others!
 
Rick, You posted while I was typing. Hope my last post explains how I view this thing. Unless I could find specific language in both the code and the manufactures listing, I would agree with you that one would have to go with the more restrictive. As I said, the codes are minimum standards. There is nothing wrong with going beyond that. The problem inspectors have is that we can't make you go beyond the standard. You as a consumer or installer certainly can.
 
I was trying to say, chief...in a roundabout "clever" way, that I don't think you're stupid. I think you and I are on the same page here. I'm glad I'm not in your shoes, having to tell someone who interpreted the conflicting requirements more liberally that you're not going to sign off on it. The standard needs to be "the standard"...it appears in this case that we might have two different "standards" on our hands. Not a good situation. Rick

(How's our hero doin' now that he's back home safe & sound?)
 
fossil said:
I was trying to say, chief...in a roundabout "clever" way, that I don't think you're stupid. I think you and I are on the same page here. I'm glad I'm not in your shoes, having to tell someone who interpreted the conflicting requirements more liberally that you're not going to sign off on it. The standard needs to be "the standard"...it appears in this case that we might have two different "standards" on our hands. Not a good situation. Rick

(How's our hero doin' now that he's back home safe & sound?)
Click to expand...
Rick, Thanks. Sometimes they think I am stupid. lol. Often times the code is specific and other times it isn't. For example.....sometimes it says "18 in., Exception - when reduced by a manufacturer listing" ( I made that up of course, but you will find similar in the codes) When it isn't specific, as in this case, I agree with you and BeGreen (and Monday I am going to look at NFPA to see and wish I could look at the stove listing too) . In this case I would tell the installer that your stove listing may allow less clearance but the single wall pipe must still be 18 inches, unless the stove listing specifically states that it can be reduced. And then I would make myself very clear.....and say I believe this is an oversight and I would strongly discourage reducing the single wall clearance. If there is not specific language in the stove listing about the single wall, then you will have to increase the allowed stove clearance to accomodate the pipe clearance.

My son is adjusting. It is difficult, but we are so glad to have him back and he is glad to be here...just a big change from where he has been for 9 months. Thanks for asking. We are baby sitting tonight so they can go out on the town.
 
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