Combustibles question

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.
First off - our stove/wall space is plenty fine. My question is about splits. I have taken to laying out the days worth of splits around the stove (which sits on tall legs) in fairly close proximity. The splits are just the teeniest bit damp still and after a day of hanging out as individuals around the stove they burn so much better. Obviously. I'm not getting productive heat out of them without doing that...maybe 350 degrees on the stove top. I'm ever vigilant about any sparks. Don't throw anything at me when I ask this...how much am I flirtin' with disaster? Yes, I know the splits are combustible. They're beside the stove (within 18 inches) for the day. It seems to be fine, but being by myself most of the week I think I'm getting paranoid.
 
Well, I don't know what everybody else says but I have been doing the same thing for thirty years.
 
I think you could do it forever and not worry about it. Unless one of them happened to fall against the stove and lean against it for a long time, then you might have a problem.

The thing I would worry about is all the bugs that live in the wood, as soon as the wood warms, the bugs might crawl out and make a new home. :ahhh:

My wood goes straight from the porch into the fire.


Robbie
 
Robbie said:
I think you could do it forever and not worry about it. Unless one of them happened to fall against the stove and lean against it for a long time, then you might have a problem.

The thing I would worry about is all the bugs that live in the wood, as soon as the wood warms, the bugs might crawl out and make a new home. :ahhh:

My wood goes straight from the porch into the fire.


Robbie


Luckily, bugs are one of the few things that don't rattle me. I'll just scoop them up and cart them out. Thanks for the confidence booster though. Now I can lay my morning wood out for an overnight bake near the stove and still get some shut eye.
 
Paranoia and fear of fire are good things, your subconscious is telling you something "Clearance to combustibles" is how far away the fire chief and your home insurance company want those splits, just bring in more wood and keep it a little further away.
 
I don't think it's the greatest thing, but I don't think it's that unsafe either. The distance to combustibles number is mostly talking about fixed things like floors, walls, and other permanent building structures that have the potential to get overheated after PROLONGED exposure.

It's a question of time / exposure / distance - the closer the distance, the less time it potentially takes for combustion to occur, the farther the distance, the more time, going asymptotically to an infinitely long time. The distance to combustibles number is based on the idea of keeping stuff far enough away that it will "never" get hot enough to have a problem.

This implies that getting closer will cause a problem if you keep things there long enough, but not if the time is kept reasonably short. Given that the logs are only being kept overnight at close range according to the OP, it doesn't sound like a big issue.

I would probably look at two main things that would help make the decision...

1. Are the logs placed in such a way that there is no real possibility of them falling or getting pushed into closer proximity?

2. How hot do the logs feel when you go to load them into the stove after sitting for a while, particularly the end closest to the stove. If the log is uncomfortably hot to the touch, then I'd worry; if it were only slightly warm or less then I would say it's not a problem, just be real rigourous about 'rotating the stock'.

Gooserider
 
You might be able to do this for the next 30 years and have no problems whatsoever, but there is a chance that something will happen out of the ordinary and you will lose your house. How much risk are you willing to take? In regards to CTC being more for permanent structures I would have to disagree. There is a lot better chance of something that can be rolled around or fall over on the stove to start a fire than a fixed piece of drywall 18 inches away. On a different note, people have pictures on here all the time of their pet laying next to the stove, and last time I checked, they are combustible. Once again it all comes down to how much risk are you willing to accept. If it ever does start a fire, your insurance company will definitely let you know their feelings on the subject.

Better safe than sorry.
 
Metal said:
You might be able to do this for the next 30 years and have no problems whatsoever, but there is a chance that something will happen out of the ordinary and you will lose your house. How much risk are you willing to take? In regards to CTC being more for permanent structures I would have to disagree. There is a lot better chance of something that can be rolled around or fall over on the stove to start a fire than a fixed piece of drywall 18 inches away. On a different note, people have pictures on here all the time of their pet laying next to the stove, and last time I checked, they are combustible. Once again it all comes down to how much risk are you willing to accept. If it ever does start a fire, your insurance company will definitely let you know their feelings on the subject.

Better safe than sorry.

Note that in my post I did say the CTC number was "MOSTLY" about fixed things. There is risk in all stuff, the OP was asking how much risk this particular action involved, and my feeling (and general concensus seems to agree) was "Not a lot", especially if following the two precautions that I mentioned.

Eliminating all risks isn't realistically possible, but understanding the risk factors can lead to more intelligent evaluation than just blind acceptance. Would I build a permanent wall w/in the CTC distance? No way. Do I see a great deal of risk in short term storage of fairly non-combustible firewood (It's not crumpled newspaper we're talking about) at less than the CTC, but still a fair way away from the stove? Not really.

Oh yes, I don't know about your pets, (note that Pet Rocks are NOT combustible...) but most of the ones I've seen are smart enough to MOVE if they get overly hot... %-P

Gooserider
 
I'm just saying CTC is CTC and it doesn't matter if it is toilet paper or firewood. If you want to be safe, follow the CTC in the installation manual which were arrived at through testing at UL, if you would rather just trust the words of someone who has never seen your stove or "drying method", so be it and good luck.
 
Hey, this has been addressed by the National Fire Protection Association in NFPA 211 2006 Edition. I found this footnote to the table for standard clearances for solid fuel burning appliances - "a Provisions for fuel storage shall be located at least 36 in. (914 mm) from any side of the appliance."
 
Bugs are the least of your problems since they won't burn your house down.

Combustion of wood occurs as the cellulose in it decomposes from a heat source (pyrolysis). This decomposition of cellulose results in gas formation which reacts chemically with oxygen in the air causing the flame and burn. Since there are several factors (heat method and rate of heating, thickness of the wood, amount of moisture in wood, etc) that determine the pyrolysis of wood, its exact ignition temperature varies (300* - 600* F). (http://virtual.vtt.fi/virtual/innofirewood/stateoftheart/database/burning/burning.html)

Therefore, unless you know specifically the variables you are dealing with by placing wood next to your heat source, especially left unattended, you are at increased risk of an unwanted fire in your home.

Aye,
Marty

Grandma used to say, "Better safe than sorry."
 
Metal said:
When dealing with life safety issues you need to be obscenely conservative. What is a reasonable risk factor? Would it be okay if only 5 out of 100 installations caused a house fire? How about 1 in 1000?

The thread was on storing a little bit of wetter (read not ready to burst into flame) then normal wood at a reasonable (IMO) distance for a short period of time, while someone was awake and nearby if I remember correctly. UL scripture is not going to be directly applicable.

If you don't peak over the edge now and then how do you know what's there? I refuse to blindly believe everything the elders say and so have to do my own spot testing.
 
"...being by myself most of the week I think I’m getting paranoid."

If the poster admits to becoming "paranoid" (aka unreasonably anxious) about storing wood near a heat source, then it's time for more caution, not less.

Aye,
Marty

Grandma used to say, "Throwing caution to the wind is the folly of youth."
 
Andre B.:
And UL is never wrong and safety standards are never obscenely conservative.
NOT
My point exactly... The reality is that we have finite floor space, and the wood has to go somewhere. The code is based on nothing being allowed to ever go wrong, no matter what. "Pushing" the code a bit can be problematic, but also lead to more liveable solutions.

Marty S:
Combustion of wood occurs as the cellulose in it decomposes from a heat source (pyrolysis). This decomposition of cellulose results in gas formation which reacts chemically with oxygen in the air causing the flame and burn. Since there are several factors (heat method and rate of heating, thickness of the wood, amount of moisture in wood, etc) that determine the pyrolysis of wood, its exact ignition temperature varies (300* - 600* F). (http://virtual.vtt.fi/virtual/innofirewood/stateoftheart/database/burning/burning.html)
Probably true, I haven't checked your numbers, but they sound about right. Assume they are... Earlier I suggested checking the temperature of some of the splits after they had been sitting for quite a while, and that it indicated a problem if they felt more than slightly warm to the touch. Other discussions, and my own experience says that equates to approx. 100-120*F; more than that will feel HOT, which I said was a problem. Granted that's an attended check, but I can't see anything that would cause a split to detect that it was unattended and decide to more than double it's temperature... This is especially true given that a split is going to have a higher moisture content (the OP said they were damp) and greater thickness, pushing the ignition temp for a split towards the high end of the range you give.

I saw the CTC testing setup when we went to VC, where they have a special set of moveable walls (painted black for maximum heat absorbtion BTW) that are heavily instrumented. These walls are moved back and forth to find the closest distance where the temperature doesn't exceed a certain minimum threshhold. I forget the exact number, but it was HIGHER than my suggested "warm to the touch" spec that I was suggesting a little while ago.

tutu_sue:
Hey, this has been addressed by the National Fire Protection Association in NFPA 211 2006 Edition. I found this footnote to the table for standard clearances for solid fuel burning appliances - “a Provisions for fuel storage shall be located at least 36 in. (914 mm) from any side of the appliance.”
Note that this is as high or higher than any clearance to fixed walls for an "unnapproved" stove, and is obviously a very conservative number.

Note that in this I am NOT advocating that one should violate codes, but I am suggesting that intelligent analysis of what the numbers really mean, and where they come from allows one to evaluate the likely increase in risk from a given "push" on the code. My evaluation is that the increased risk of this particular method is pretty low, probably less than that of splitting wood with a monster-maul in a thunderstorm (which I would not reccomend)

Gooserider
 
Consider there may be more than spontaneous combustion of wood stored close to your really hot stove. Maybe somewhere along the line, someone opened their stove door and there was a pop and they didn't realize an ember landed on the wood close to the stove, then they went to bed and a tradgedy ensued. Or didn't realize a a hot coal fell off the shovel onto the wood as they were carrying ash to the can they forgot to bring closer. I don't think those are impossibilities...
 
Gooser...:

First, they're not my numbers. Check the reference.

Second, "...approx. 100-120*F; more than that will feel HOT," . What's the relevance? We're talking flash point of wood.

Aye,
Marty
 
Marty S said:
Gooser...:

First, they're not my numbers. Check the reference.

Second, "...approx. 100-120*F; more than that will feel HOT," . What's the relevance? We're talking flash point of wood.

Aye,
Marty

If it's in your message, it's your numbers - as I said, I am assuming that you quoted your reference accurately - why are you quibbling?

Go back and read my earliest post in the thread - I said that as long as the ends of the splits closest to the stove felt no more than warm then things were probably REASONABLY safe - not totally or completely safe, but reasonably so, meaning a level of risk that is unlikely to result in harm, especially if one is reasonably cautious about sparks, embers, and such.

I also said that if the wood felt HOT then it was probably not safe. Since you seemed unclear about this, I was pointing out that this provided a 100-200% safety margin over the LOWEST number you cited, increased by the fact that cordwood is more likely to be on the high side of that range.

Relevance is that it's a quick and easy way of gauging the likelihood of getting combustion - spontaneous or otherwise - cold or just warm is unlikely at most, hot to the touch more likely, burning to the touch risky.

Sue - Yes it is possible that an unseen spark or ember could start a hunk of cordwood going, but it's only slightly more likely than having said peice of cordwood undergo spontaneous atomic disintegration. It's why we use kindling when we start a fire - a match, or a spark, or an ember is most unlikely to be able to carry enough heat energy to get a split going in the absense of kindling material.

Gooserider
 
I do that all the time myself and don't worry about it. We do have a much larger hearth than required, so part of the wood is not inside the required clearance range, but of course it is within the 36" that they say not to have anything combustible. I have the wood laying down, so unless there is an earthquake, the wood isn't moving. (No pets or kids or poltergeists here.) It would depend on your stove and how hot it gets around it. Our particular soapstone stove only gets up to 350 F on the top, and we have taken extensive temperature measurements of the nearest wall, under the stove, etc. No other area is nearly as hot as the top, so I would have to say that at the distance the wood is from the stove, and not becoming noticeably hot, there is NO WAY my wood is going to spontaneously combust. Given the trouble of getting a fire going in my stove when there are a few hot coals, I also have little fear of a spark escaping and then setting a slightly damp piece of wood on fire. Also, the stove door is in front and the wood is mainly on the sides and back, so sparks wouldn't tend to go there. I worry a lot more about the couch nearest the stove. Plus, if a piece of wood on top of the tile somehow burned, it would most likely be contained on the non-flammable tile. We do keep an attractive widemouthed vase full of water near the stove all the time, for flinging at sudden sparks if necessary. Only used it once, on the floor in front of the hearth when a small hot bit jumped. Yes, you could come up with a scenario that is dangerous, but probably you are more in danger from eating too much beef or potato chips or something.

I frequently make and can jam, salsa, etc., and I reuse mayo jars and the like all the time. This is not advised, and people are always telling me how this glass will break. I have canned over 500 jars of stuff in the past 3 years (lots before that, too, but that is the only statistic I have.) The only jar that broke was an official canning jar, and that is because I dropped it TWICE. So I let that advice go in one ear and out the other. As long as the wood doesn't sit there for weeks getting really dried out I don't see a problem. Just don't let the wood touch the stove of course. Disclaimer: I am not an expert, and don't play one on TV.

Has anyone ever heard of a house fire from damp wood being dried near the stove?!? I can't imagine it in a case where the wood was not touching the stove directly. This isn't like overloading an electrical circuit or chainsawing without protective gear or something definitely, unarguably dangerous.
 
Look at it the way UL does in the test of clearances. If the item can get to 115 degrees over ambient room temp then it is too close. If the room is 70 degrees and the wood can get to 185 degrees, it is too close.
 
Status
Not open for further replies.