What’s wrong with this picture?

[Doc C]

There are several threads here on hearth building for the 13NC. Micore 300 is typically used as a base to rapidly build up R value. 1" = R2.06.

Yep. That's some of what I'm reading. I don't have access to anything that fancy I don't think. I have a home depot. And I don't recall seeing that there.

 

[begreen]

Search on 13 NC hearth. Lots of threads will show up. Here are a couple.
https://www.hearth.com/talk/threads/2-0-r-factor-hearth-pad-for-13-nc.146091/
https://www.hearth.com/talk/threads/new-guy-hearth-pad-questions-for-englander-13-nc.90563/

 

[begreen]

Looks like micore is sold in Idaho Falls and Rathdrum, ID. You could also go with Durock NexGen layers on steel studs. Or like bholler said, just a lot of layers of Durock NexGen.

 

[WoodyIsGoody]

Very good you can do some research.

You are right they want to set the clearances at something they know they can pass. But guess what they don't do it by guessing. They do it with in-house testing. So they know what the results are before they go for the expensive ul testing. So no there would be no financial benefit for them to needlessly increase their clearances.

Sigh...I never said they needlessly increase the clearances. They need to make an educated guess so it will pass the first time because they don't want to pay for a failed test run. It's expensive. Even if they do in-house testing, trying to replicate the independent test (which you've offered no evidence that they do), it's still an educated guess. There's definitely a margin built in to their guess and the margin will be based on their tolerance for having to do it twice. Testing is variable. They never "know" what the results will be, hence the margin.

You can tell me how you think it is but without supporting evidence your claims are hollow.

The bottom line is this is not nearly the exact science you presented it as. There are margins added in all over the place, from variables in every test run to how hot UL decides is an acceptable standard to how much tolerance the manufacturer has for potentially paying to do it all over again. Chances are, many manufacturer's make an educated guess based on previous testing of similar models rather than trying to replicate the UL test in-house for every single model because that would cost a lot. The woodstove market is very price sensitive, particularly when selling stoves at the competitive end of the pricing scale. The people who do the test need to be paid whether in-house (for trial runs) or at the independent testing lab. It all costs money.

Yes, in the end they come up with a number that passes and gets certified. It's a number compromised by practical considerations like wanting to pass the test the first time. Some manufactures will work harder to make sure the number is nearly as good as they can hope for, others will do it on the cheap and pick an easy number that will easily pass.

In my mind, the theory that these numbers are a good and accurate indication of when the wood underneath will risk ignition due to high under-hearth temperatures is awfully naïve. Yes, we need to meet the published minimums due to insurance and building codes but the numbers are not an accurate predictor of anything.

The only thing you can bet your platinum plated panties on is that if you meet these numbers you don't need to worry (at all) about the wood under your hearth unexpectedly bursting into flames.

 

[edyit]

The only thing you can bet your platinum plated panties on is that if you meet these numbers you don't need to worry (at all) about the wood under your hearth unexpectedly bursting into flames.

that's what i want is to not have to worry at all. you're bringing fire into your house. it is so much easier to follow the clearances and know there is no chance of something coming back to bite you in the ass later. hell if anything on the ones i've helped put in for myself and a few others we've exceeded clearances / hearth requirements. always better to err on the side of caution.

 

[bholler]

Sigh...I never said they needlessly increase the clearances. They need to make an educated guess so it will pass the first time because they don't want to pay for a failed test run. It's expensive. Even if they do in-house testing, trying to replicate the independent test (which you've offered no evidence that they do), it's still an educated guess. There's definitely a margin built in to their guess and the margin will be based on their tolerance for having to do it twice. Testing is variable. They never "know" what the results will be, hence the margin.

You can tell me how you think it is but without supporting evidence your claims are hollow.

The bottom line is this is not nearly the exact science you presented it as. There are margins added in all over the place, from variables in every test run to how hot UL decides is an acceptable standard to how much tolerance the manufacturer has for potentially paying to do it all over again. Chances are, many manufacturer's make an educated guess based on previous testing of similar models rather than trying to replicate the UL test in-house for every single model because that would cost a lot. The woodstove market is very price sensitive, particularly when selling stoves at the competitive end of the pricing scale. The people who do the test need to be paid whether in-house (for trial runs) or at the independent testing lab. It all costs money.

Yes, in the end they come up with a number that passes and gets certified. It's a number compromised by practical considerations like wanting to pass the test the first time. Some manufactures will work harder to make sure the number is nearly as good as they can hope for, others will do it on the cheap and pick an easy number that will easily pass.

In my mind, the theory that these numbers are a good and accurate indication of when the wood underneath will risk ignition due to high under-hearth temperatures is awfully naïve. Yes, we need to meet the published minimums due to insurance and building codes but the numbers are not an accurate predictor of anything.

The only thing you can bet your platinum plated panties on is that if you meet these numbers you don't need to worry (at all) about the wood under your hearth unexpectedly bursting into flames.

Yes of course there are margins built in I never said there weren't. But your completely uneducated assumption that the numbers are not an accurate predictor of anything is incredibly naive.

And yes of course at those numbers you don't have to worry about spontaneous combustion. And do you know why??? Because it has been tested. Try to keep up we said that 20 posts ago.

 

[VirginiaIron]

Here is a question from 2008

https://www.hearth.com/talk/threads...ove-do-i-still-need-to-cut-away-carpet.17516/

 

[WoodyIsGoody]

Yes of course there are margins built in I never said there weren't. But your completely uneducated assumption that the numbers are not an accurate predictor of anything is incredibly naive.

One reason the numbers are not an accurate predictor of anything (beyond that they are safe numbers) is because the margins you agree exist, vary widely from stove to stove. Because there is no way for the consumer to tell if a particular stove passed the hearth temperature test by a gnat's eyelash or an elephant's dong, there is no consistency there. All we know is the tested stove passed the test one time with those numbers.

Secondly, because the UL standard is a private, unpublished standard, the consumer has no way to tell if the install of a stove that passed the hearth temperature test by a gnat's eyelash is just one over-fire away from the hearth bursting into flames or if the standard is extremely conservative in this regard.

Between not knowing whether a particular stove passed by a little or a lot, and the unknown margin of safety built into the standard, the numbers are not an accurate predictor of anything meaningful (other than being safe numbers).

You don't need a Nobel Prize in statistics to see that simple truth.

 

[Doc C]

Drink coffee, light a fire, move on...but elephant dong...lol that's funny.

I'm scared to ask this. Because i dont want to ignite another argument.

We have beaten the dead horse to death about outside air kits over the years.

In our area when we sell a house we have to have an outside air kit or proximity air built into the hearth or we have to pay money to have it done at closing.

We are selling the house next year,

I can not use an outside air kit because of the way my rafters are under the hearth.

If I use a proximity air air under the stove doesn't that defeat the purpose of all the r value I'm doing? I mean I will just have a vent straight down to the wood subfloor and crawl space.

 

[WoodyIsGoody]

If I use a proximity air air under the stove doesn't that defeat the purpose of all the r value I'm doing? I mean I will just have a vent straight down to the wood subfloor and crawl space.

You could remove any doubt by lining the vent cut-out with the same materials you insulate your hearth with before installing a metal vent.

Probably overkill but better safe than sorry.

 

[Highbeam]

Drink coffee, light a fire, move on...but elephant dong...lol that's funny.


In our area when we sell a house we have to have an outside air kit or proximity air built into the hearth or we have to pay money to have it done at closing.

We are selling the house next year,

I can not use an outside air kit because of the way my rafters are under the hearth.

If I use a proximity air air under the stove doesn't that defeat the purpose of all the r value I'm doing? I mean I will just have a vent straight down to the wood subfloor and crawl space.

You're selling next year? I would have stuck it out with the NC30 then and not started this project at all. Might not even reline the chimney unless you're afraid it will cause a failed inspection. Oh well, too late now. Exciting to be moving. Bring in the real estate agent to have her guide your improvements. My ugly BK, for example, would probably not help sell the house!

 

[Doc C]

You're selling next year? I would have stuck it out with the NC30 then and not started this project at all. Might not even reline the chimney unless you're afraid it will cause a failed inspection. Oh well, too late now. Exciting to be moving. Bring in the real estate agent to have her guide your improvements. My ugly BK, for example, would probably not help sell the house!

We had the house on the market this year and had 2 full price offers that fell through because THEIR house failed to sale even though they both had offers on it. Our agent is a friend of ours so she is here all the time.

We ran out of time before winter to try to find another buyer so we are waiting until spring.

Our house is remodeled almost completely but the living room was one thing that people said they did not like the way it was. And I agree completely!

Our agent figured we could ask another $5k or so if we restructured the living room to make it more user friendly.

We had 2 chimney inspections. 1 said it was fine and 1 said it could use a reline. But they wanted to do the refractory coating.

After talking to folks here and also a 3 chimney company I decided to go with the company that said it did not need relined. And to do the pipe.

I figure I don't know who is going to be inspecting the chimney the next offer we have so I might as well do it on my terms.

Also I would feel horrible if I found out the house burned down after we sold.

I always try to what's right no matter what. Let's me sleep better! Not that I sleep very good anyways.

 

[Hogwildz]

Most times, what is blamed on the stove, is not the stove's fault. You may find unless you fix the cause(s) of the issue, no matter what you throw in there will have the same issues. You're throwing a lot of cash at a problem you're not sure of the cause of. Too much heat is a matter of loading smaller loads or larger pcs., just not to the gills. I have had plenty of smaller loads burnt without any problems, many do it here. Same coffee can of nice brown fluffy cleanings every year.

You don't have to go down to hook up an OAK, there are other options.

There is a the rare occurrence the issue may be the stove itself, but the percentages are very low.
I think you've jumped the gun, without finding out the cause to the symptoms.

You've also contradicted yourself stating you want to do it right, yet chose to forgo the insulation and go the cheapest, easiest route.
Cheapest, easiest is one theory that is not the best when dealing with wood burning appliances, especially if you're worried about the next owner suffering a burned down home. If that's the case, pull the stove and close everything off. Done deal

 

[Doc C]

Most times, what is blamed on the stove, is not the stove's fault. You may find unless you fix the cause(s) of the issue, no matter what you throw in there will have the same issues. You're throwing a lot of cash at a problem you're not sure of the cause of. Too much heat is a matter of loading smaller loads or larger pcs., just not to the gills. I have had plenty of smaller loads burnt without any problems, many do it here. Same coffee can of nice brown fluffy cleanings every year.

You don't have to go down to hook up an OAK, there are other options.

There is a the rare occurrence the issue may be the stove itself, but the percentages are very low.
I think you've jumped the gun, without finding out the cause to the symptoms.

You've also contradicted yourself stating you want to do it right, yet chose to forgo the insulation and go the cheapest, easiest route.
Cheapest, easiest is one theory that is not the best when dealing with wood burning appliances, especially if you're worried about the next owner suffering a burned down home. If that's the case, pull the stove and close everything off. Done deal

Wow. I'm guessing maybe you skimmed the posts? That's OK, there is alot to read.

I have been working on the problem for 3 years. Consulting several very knowledge people on here, local chimney companies, and countless hours of reading.

I addressed EVERY solution that was presented except relining the chimney which is in the process and WILL be insulated.

I needed a smaller stove anyways since our home is insulated to standards that are much much higher then most houses included air sealed very well with proximity air added in the same room as the stove just not where local rules insist that it be.

My chimney is on an interior wall and my floor joists are in the way for OAK.

Maybe you got a couple different threads mixed up but I will never take the cheapest easiest way out on anything.

Everyone in my family gives me a hard time because I OVERBUILD everything!

They also give me a hard time because I can almost heat my house with a couple of candles.

Also I ran the new stove for a day to see if the problems were gone and from what I can tell in only 1 day of running the stove they are gone which tells me either my old stove had problems OR the new stove is more compatible with my setup which is probably more likely.

But I do appreciate the constructive criticism even though it might be due to misinformation in this case.

The one benefit of your post is that if other people are reading it then it will reinforce the need for them to do it correctly and safely!!

 

[begreen]

Doc, if an outside air kit is required for the house sale then so be it. Your goal of doing the right thing for the next owner is admirable.

The OAK connects horizontally into the back of the stove. I'm wondering about the OAK come up behind the stove. Is it due to floor joist framing at the chimney base? If 3" round won't pass up to just behind the stove is there room for a rectangular box, like say 1" x 6" between floor joists?

 

[Doc C]

Doc, if an outside air kit is required for the house sale then so be it. Your goal of doing the right thing for the next owner is admirable.

The OAK connects horizontally into the back of the stove. I'm wondering about the OAK come up behind the stove. Is it due to floor joist framing at the chimney base? If 3" round won't pass up to just behind the stove is there room for a rectangular box, like say 1" x 6" between floor joists?

An outside air source is required. It can be an OAK or it can be just a vent in the floor. Which is what I have to use in this case.

I'm just trying to figure out how I can keep heat from stove away from framing members and subfloor where the vent will be?

I'm leaning towards what WiG suggested about lining it with the next Gen I'm using.

Unless there is another idea? My original though was to put the vent will directly below the stove to where you can't see it. But now as I write this I'm questioning that idea. I wanted the vent hidden

 

[begreen]

Don't worry about the heat. This is at the shielded back of the stove and very low. The hearth protection will easily protect the wood underneath. The hottest area of the hearth is going to be in front of the stove, not behind it.

 

[Doc C]

Don't worry about the heat. This is at the shielded back of the stove and very low. The hearth protection will easily protect the wood underneath. The hottest area of the hearth is going to be in front of the stove, not behind it.

So you would consider it safe to have the vent UNDER the stove? That would be my preference.

 

[begreen]

So you would consider it safe to have the vent UNDER the stove? That would be my preference.

Yes, especially if at the rear of the stove and not blocked by the base. Or, for a tighter connection, with a plenum box that is tied to the stove's oak connection.

 

[VirginiaIron]

I would think the OA would provide enough cooling of the surrounding surfaces, especially ifons you are operating below 30 degrees.

 

[VirginiaIron]

I prefer to sleep well at night rather than thinking I skimped to close to or short of code.

 

[Doc C]

Where the tape measure sits is the center of the stove. I'm going to put the vent right there and if I understand everyone correctly it should be fine.

 

[begreen]

If possible I'd bias it more toward the rear of the stove. The base on this stove opens on the East and West sides. The oak intake is at the rear.

 

[Doc C]

If possible I'd bias it more toward the rear of the stove. The base on this stove opens on the East and West sides. The oak intake is at the rear.

I think I can do that. I'll have to bring my air in through small 1" holes in the subfloor and then through a vent on the hearth but that should work I would think. Maybe a couple extra holes So I have like 5" of air inlet instead of the 3" an OAK would provide.

 

[VirginiaIron]

I think I can do that. I'll have to bring my air in through small 1" holes in the subfloor and then through a vent on the hearth but that should work I would think. Maybe a couple extra holes So I have like 5" of air inlet instead of the 3" an OAK would provide.

Are you planning on cooling that platform with 5 one inch holes?