# My house almost burnt down today do to cedar wood dust.. watch out..!!



## Bsigns (Jun 30, 2012)

We got woke up to people banging on our front door in the early AM today good thing i did not shoot them.
Open the door with them yelling your porch is on fire.

They were out having a morning walk and noted that our front porch was on fire. Me and my wife grabed pots and pans and filled them with water and started putting it out as i also called for the fire dept.

We got most of it out before they got here but it was still smoldering.
I had no clue how a fire could of got started we have no wires or anything by the porch in that area.

After looking the fire dep says it was Spontaneous combustion that cedar dust i had been putting down all around edge of the house just started and bust into flames on its own.

I make cedar signs and i have been dumping all the cedar dust from my sander and cnc routers all around the edge of our home thinking this was a good way to keep bugs out and it looks good.

It turns out that cedar and many others wood products in that fine of a size can heat up inside from moisture and get molded and this created a reaction that gets so hot it can start a fire.

I still am having a hard time thinking that is what happened but that is what they say it was Spontaneous combustion of the thick cedar dist i have around the front of the porch it was around a foot thick in that area.

It was damp out and i was thinking no way with this much dampness can this happen but the dampness is what makes the bacteria or mold react even more and heat up deep inside the cedar dust pile and bacteria and self-ignite because of heat produced by bacterial fermentation.

Just wanted to post this.. Do not put your cedar dust or chips around your home or if you do make sure that it is not in a thick pile no more then 3 inchs thick to help stop it from bacterial fermentation deep inside the pile.

I now have a burned up porch i need to fix but we make it out alive..
I will be taking all the cedar dust around the house away now for sure.

Just be careful i would of never expected this to happen.


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## a1Jim (Aug 9, 2008)

Wow
This is unbelievable,who would have ever guessed that cedar wood chips could cause spontaneous combustion .
Thanks for sharing this information.


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## nailbanger2 (Oct 17, 2009)

a1Jim, I think it's important to clarify he was using cedar *dust*, not chips. Otherwise, I agree whole heartedly with your comment. I hope a lot of people read this!


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## Bsigns (Jun 30, 2012)

A few photos from my cell phone.


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## Bsigns (Jun 30, 2012)

One more showing more of the bed area.









They say it started down low in the cedar and burned up and then under the deck. Around a foot away from the side of the house.
The fire dep cut away the porch with a saw to make sure it was all out.


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## helluvawreck (Jul 21, 2010)

Wow! Thanks for the tip. I sure am glad that it wasn't any worse for you and am certainly thankful that no one was hurt or worse, and that you didn't loose your house.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com


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## Hopdevil (Dec 13, 2009)

Wow, glad you and your family are ok!

It makes me wonder however… I put a thick layer of sawdust (all kinds of wood mixed up) on my compost container periodically to keep the bugs down and provide additional composting materials. The container is right up against the house.
Should I be worried? or is this an issue with only wood in the cedar family?
Thoughts anyone?


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## Bsigns (Jun 30, 2012)

Yaa me to it was scarey for sure. I need to go and rake all that out and get rid of it now. I have it all around the house I was just going to dump 2 more bags out sometime this week i have 2 dust collectors to empty.


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## woodcox (Nov 21, 2012)

Crazy! Glad you guys are ok. I used to do tires for Waste Management garbage trucks, in their yard they would always have a few of their plastic cans that were burnt or melted down from people leaving compost or grass clippings inside. Amazing the heat that can be produced from the process.


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## woodsmithshop (Sep 10, 2008)

now I am wondering about other woods also. my dust collector has quite a bit of dust in it, can it start a fire that way too?
kinda scary.


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## danoconnor11 (Dec 27, 2012)

I've seen cedar mulch do this when I was with the fire department.


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## patron (Apr 2, 2009)

who would have guessed

glad you got it out
and are all safe

thanks for the heads up

i just blow my vacuum outside
will have to rake it thinner periodically now
cause it goes get wet when it rains


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## joeyinsouthaustin (Sep 22, 2012)

good to know.. first I have heard of this. Another reason to keep that shop clean of dust piles!!


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## crank49 (Apr 7, 2010)

I would guess the same thing might be possible with any combustible dust.
Along the same principle of bailed hay catching fire if it is not dry enough, or gets rained on, before you put it in the barn.


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## ajosephg (Aug 25, 2008)

I've also heard of lawn mowers catching fire due to grass clippings beneath the mower. Cleanliness is next to Godliness!


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## DS (Oct 10, 2011)

Out by the river bottom they have these huge composting heaps for making mulch. They have to manage them very carefully because as the organics break down they create lots of heat.

A couple months ago they had a huge fire out there that burned for almost a week because the heaps spontaneously combusted. (We're talking 100 acres or more burning)

What a mess. Glad you're okay and that the neighbors were looking out for you.


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## Bsigns (Jun 30, 2012)

Thanks everyone.

We removed it all from around the house today..


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## gfadvm (Jan 13, 2011)

Thanks for the heads up. I had no idea this was possible.


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## cutmantom (Feb 2, 2010)

Revenge, rebuild with cedar


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## NormG (Mar 5, 2010)

Wow, I read a while back about someone whose mulch pill did this very thing.

Glad to hear turned out as it did with minimal damage


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## Purrmaster (Sep 1, 2012)

Thanks heavens you are all unhurt and your house is intact. It sounds like quick thinking on your part saved the day.

They said that the wood dust spontaneously combusted? I know fine wood dust can burn if it has an ignition source. But I don't see how the dust itself would be an ignition source. Then again, I'm no expert.


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## crank49 (Apr 7, 2010)

The dust is the fuel, air is the source for oxygen, and moisture feeding bacteria created the heat. 
There you have it, the three things required for a fire.


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## Dlow (Jan 16, 2011)

This is a very common occurrence! I've seen it many times during my time in the fire service and NO it isn't limited to just cedar. The same phenomenon can occur with any type of organic material that decomposes, although some react faster than others. I'm sure many of you have heard of barns burning down that have just been loaded with fresh cut hay or seen firefighters hosing down a tanbark bed at the local shopping center or someones home, or seen the steaming piles of mulch/tanbark where it's sold. This is usually the cause. This is also the time of year when conditions are perfect for it to occur, low humidity still warm temps during the day get things nice and hot in the bed and a calm breeze blowing to stoke the smoldering embers and well you know the rest. I've even seen it happen in the dead of winter during a long cold snap too. Low humidity, a couple hours of bright sunshine and a little wind is all it takes. Like you said, if you keep your mulch bed shallow it will keep the heat from building up, but I still won't put it around my house! And you should probably buy those folks that woke you up, a nice dinner!


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## firefighterontheside (Apr 26, 2013)

Yep, I've seen it numerous times with large mulch piles. Its a pita to put out when the piles are 100 ft. tall. I've seen it just as dlow described in mulch beds also. In firefighter 1 and 2, the basic classes for firefighting, spontaneous combustiin is covered. It describes oily rags and dead or decaying material catching fire due to the heat given off by the process. As for the compost pile, you will be fine as long as you are turning it over. Still, probably shouldn't have it up against your house just in case you forget. Also this process can probably happen faster in fine dust due to the large surface area as opposed to the same weight of wood in larger chips. For firefighters its one of those things you learn about that you think will never happen, but then it does.


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## wormil (Nov 19, 2011)

I wouldn't have believed such a thin layer could spontaneously combust, especially outside with airflow.

Some interesting reading.
http://www.doctorfire.com/low_temp_wood1.pdf


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## BryanatWoodstock (Oct 31, 2012)

It could have been started by someone that dropped a lit cigarette! Seen this twice! Once a corner downtown that the city beautified with gardens and rocks. I noticed the mulch was smoldering, burnt a 2 ft area , so pulled over and emptied my bottle of water to try and put it out. Second was at a drive through at a coffee shop , the mulch in the gardens as you drive up the the window was burning from a tossed cigarette. Or maybe from spontaneous combustion as others have said!


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## Charlie5791 (Feb 21, 2012)

There's a dairy around here that heats their home and the office space in the barns from their pile of composting cow manuer and straw from muckin' out the barns. They have coils of some kind of black 1-1/2 to 2" hose buried in the pile. They circulate water in in (or maybe antifreeze or something… I don't know) and it goes through insulated pipe runs to the house and barns. Apparently the pile stays hot all through winter.


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## BillWhite (Jul 23, 2007)

I can remember as a kid in South Mississippi the sawdust piles (big piles) from the "portable" sawing sites in the country combusting from the inside. You could see a wee bit of smoke comin' from the very top of the piles.
Dad would threaten me with a serious pounding if I ever played on those piles.
Oxidation is an interesting process.
Bill


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## Planeman40 (Nov 3, 2010)

Now you've got me thinking about the wood dust I have in my dust collector bag in my basement shop. Not too much at the moment, but enough. The wood dust is dry and not damp and I think wood dust has to be damp to spontaneously combust.

Any thoughts about this problem? A lot of us have it!

Planeman


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## firefighterontheside (Apr 26, 2013)

It would need to be wet as that is what allows the decomposition.


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## Planeman40 (Nov 3, 2010)

Thanks firefighterontheside! Coming from you considering your background, it eases my mind greatly. And the numerous others here too.

Planeman


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## SCOTSMAN (Aug 1, 2008)

I wonder how brave the people were by waking you up so early, are many people shot this way? I remember two Englishmen getting shot when they ran to someones door for help thinking they were being kidnapped by a driver they didn't know the owner of the house was found not guilty seems you have a right to shoot people for banging on your front door or whatever in the USA I call it trigger happy myself . Seems the news reports encourage paranoia amongst lot's of USA citizens. Look at the number of people shot during a hurricane down deep south when news reports incorrectly said black people were looting and raping people genuine people looking for help were shot and killed. Sad so very sad .Alistair


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## Planeman40 (Nov 3, 2010)

It all depends on where you live, Alistair. I surmise you live in a rural area. I live in a big city, although in a very nice area. If someone was banging on my door here in Atlanta, Georgia, USA in the middle of the night I would figure there was an emergency and would answer the door with no gun. But if I lived in some other parts of town that have a high crime rate I don't think I would open it and would probably have a gun close by. The same probably goes for parts of London and elsewhere. From what I read here, England is no paragon of virtue when it comes to crime. Many in England wish to hell they had a gun when they find themselves beset by thugs and their life is in danger.

As for New Orleans and the hurricane, the USA news reports were correct. There WAS a lot of looting and raping! Many were in fear in certain high crime areas in New Orleans! It seems the news reports you read in England have the typical liberal bias! I have kin in New Orleans and Baton Rouge and I can assure you what I say is correct.

Planeman


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## SCOTSMAN (Aug 1, 2008)

no not according to our news reports.Now you have to admit there are lots of people who should not own guns and also as a Scotsman say what you wish re London and England it matters nothing to me even though your innacurate with your writing.We voted overwhelmingly here to be rid of guns and most feel that was a good decision when we see mass shootings we feel we did the right thing too of course there is crime here as well but the deathg penalty for innocent people based on fear and paranoia seems very disturbing. I say it is not that we are better than you or any such nonsense we clearly are not but hey you have alot of gun happy people with you and the vast majority lkike your good self are very lovely people that is my finding having been to the states many many times.We are really brothers and sisters in sprit but on guns and gun control and useage of guns we differ markedly. Alistair


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## firefighterontheside (Apr 26, 2013)

Now dry fine dust has its own hazards, but that's probably for another thread.


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## Planeman40 (Nov 3, 2010)

"on guns and gun control and useage of guns we differ markedly"

That we do Alistair. Ours here is not so much a "love" of guns but a fear of government excess which stems from our founding days fighting an overbearing and arrogant government (i.e. King George) which caused us to write into our Constitution a "right" to own guns as a deterrent to government excess. Personally, I have no guns except some old shotguns handed down from ancestors that reside unused deep in a closet. But I do believe in our right to own guns in our country and the above reason for this. At this point I don't see the need to use them against government, however one never knows about the future. And with the trend in government here in the USA trending to be an overbearing one I hope the fact the population is armed gives pause to certain of our politicians ambitions. 

Planeman


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## lab7654 (Mar 31, 2012)

I worked at a dairy farm covering piles of silage (chopped corn), and those piles were burning hot even 8 inches down. Guess this happens in plenty of situations.


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## 280305 (Sep 28, 2008)

I have to say that this is the first thread I have seen discussing, in parallel, steaming piles of rotting organic matter and politics.


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## Purrmaster (Sep 1, 2012)

So essentially the sawdust turned into a compost heap, which got hot by microbial action and that provided the heat to start the fire?

Maybe I should clean the enormous pile of sawdust out from under my table saw.


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## carver1942 (Sep 25, 2013)

Sorry to hear about your fire. Glad to hear you got out safely and were able to control it. I remember a young person. my dad who was a carpenter, telling me to never leave sawdust around. It would ferment if it gets damp, and start a fire. I always clean up after every job now, no leaving it around.
Ed


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## reedwood (Jan 27, 2011)

Man, that was close! You might want to give those neighbors a bottle of wine or a gift card!

another thought…you should research or ask your gardener whether this is helping or hurting your plants.

My understanding is in large quantities, it takes nutrients away from the plants more than it adds. But, cedar chips are OK, not the same.

hey, any pyros in the crowd? I have a burn pile for my landscaping and I like to throw a big shovel full up in the air over the fire…....WHHOOOOOOOOOOSH!!! .....HA! come on, what kid doesn't like a nice big ass fire ball?
( trained navy fireman/ volunteer fireman, hose is nearby, allowed in county, burn pile shared with neighbors, in the open, no kids near, never had an accident, never left alone, never left burning, safety first, .... etc.)

and, BTW, I own a few guns…......BOO!....... you guys crack me up.


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## Planeman40 (Nov 3, 2010)

The same with oily and waxy rags.

My Dad made an impression on me when I was a teenager working on old cars and beginning to build a shop. He admonished me about leaving oily rags around and made me put them in an enclosed steel container. Dad was a WW-2 U.S. Navy pilot and he told me about a large fire on his base at the parachute loft caused by waxy rags. It seems there was a long Masonite-topped table used to repack parachutes. The table was kept thoroughly waxed to keep the silk parachutes from snagging on the table top and to ease the shifting around of the fabric. After a thorough investigation of the fire it was determined that it was the improperly stored waxy rags that started the fire.

I still think of his tale when using rags of this nature and always keep them in a strong steel container with a good top on it.

Planeman


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## Ken90712 (Sep 2, 2009)

Man, so glad you guys are OK… I thought about what you said about not shooting them and had to laugh. As I am the same, but how did we become that way? I have a no solicitor sign up and I work nights but they insist on banging on the door and waking me up. When I say they can't you read they get all upset and tell me they have a right to make a living? When the doorbell does ring and it's a buddy or neighbor I remember not all the rings are bad….

One suggestion, A while back I had a Router catch fire on me in the shop. Lucky for me I have fire extinguishers in the shop, garage, kitchen and bedroom. Over kill but peace of mine. I only suggest this as you mentioned you were getting pots and pans… 
Glad all is ok.


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## redSLED (Mar 21, 2013)

Incredible. Good thing no one got hurt. Thanks for taking the time to post this.

Guess you're not building your new porch out of cedar?


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## Underdog (Oct 29, 2012)

Wow! Glad no one was hurt!

Never thought about a fire with wood chips or sawdust, but it sure makes sense.

I used to compost the manure/hay mixture from our barns when I lived in Alaska. Even at -50° F. it was hot enough to melt off several feet of snow and be steaming all the time. Sure did make good compost though.


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## Loco (Aug 11, 2013)

Go buy a couple of fire extinguishers. Like RIGHT NOW. One for the shop and one for the kitchen.


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## SCOTSMAN (Aug 1, 2008)

steaming piles of rotting organic matter and politics.

isn't there a direct correlation on both sides of the pond.LOL

anyway king George and alll royalty were dirty ba$tard$ and there actions towards USA at that time was simply appaling I AGREE WITH YOU demanding taxes and preparing to kill to get them still you soon showed that English rogue were to go didn't you and we will soon tell the present royalty were to go when Scotland divides itself through seperation for westminster and all royalty contained therein.LOL 
see Say what you like re England I am Scottish it's like me arguing the usa politics and demanding an apology from a canadian.LOL


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## SCOTSMAN (Aug 1, 2008)

Ps I still love the USA and it's people England and it's people and canada and it's people LOL but serious. Alistair


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## Planeman40 (Nov 3, 2010)

Well Alistair, I am of Scottish decent too from all sides of my linage with a touch of Alsatian and Austrian thrown in. I guess if it is good enough for the Queen I can tolerate it.  The mostly Scottish part accounts for my rebellious side. It is often said in my part of the USA - the southeastern part - there are more people of Scottish heritage than in Scotland!

Planeman


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## DS (Oct 10, 2011)

Spontaneous Combustion is serious stuff…
This fire is still burning.


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## MrRon (Jul 9, 2009)

I'm going to clean out that mess of sawdust in the bottom of my cabinet saw.


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## Purrmaster (Sep 1, 2012)

And as Mr. Scott has told us, Scotts make the best engineers.


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## ssnvet (Jan 10, 2012)

Wow!

Glad you caught it b4 you lost your house and that no one was hurt.

Any chance any of the dust had BLO or other finish in it?


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## joeyinsouthaustin (Sep 22, 2012)

This fire burned for over a month…we had to smell it from the shop for weeks… look at the price tag too… glad your ok.


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## pdbernardo (Jan 8, 2012)

That happened around the corner from us to people who put down too thick piles of cedar mulch. Piles of leaves will occasionally heat up like that too, and could combust. If you have a thick pile of organic stuff, even when it's mulch or compost, you have to keep moving it to cool off the center (and aerate the pile).

Glad to hear that nobody got hurt.


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## verdesardog (Apr 2, 2011)

I am a member of the society of primitave tecnology and I make fire by rubbing sticks together. Embers can be formed at tmeperatures as low as 200 degrees F.


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## b2rtch (Jan 20, 2010)

I am not surprised! 
Did you tried to put your hand in a compost pile? 
It get extremely hot and sometime it start to burn. 
This is why many garbage dumps burn.
Thank you for the warning anyway.


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## PaulDoug (Sep 26, 2013)

My brother sawed some oak boards at my parents house once. Got done and left. the oak was hard to cut and did some smoking. the sawdust sat and smoldered under the table saw. cause smoke damage to the house. Couls have started burning destroyed the house. Pays to be careful and clean up.


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## bigk (Jul 9, 2009)

Fine sawdust can be a real fire hazard for many reasons. Owners of larger dust collectors that are fully inside of the shop are advised by the manufacturers to empty the dust collection bins nightly. I think that NFPA, within their codes or rules, also requires commercial shops to empty their dust collection bins nightly also. Besides the possibility of spontaneous combustion is the real danger of a stray screw or bit of metal being introduced into the dust collector that causes a spark on impact with the impeller. That small spark may smolder in the sawdust and finally flame up during the night. What about if you were to cut or machine some wet wood. Wouldn't that introduce some moisture into the saw dust pile? How much moisture? I guess that depends on many variables obviously.

It seems that I have also heard somewhere about a heavy buildup of sawdust on top of a fluorescent light fixture being ignited by the heat of the ballast of that fixture. I do know that accumulated sawdust does provide an excellent pathway for quickly spreading a starting fire.

Anyways, the only reason that I have provided any of this is to make you all aware that sawdust in the shop is a hazard for more reasons them just spontaneous combustion. Just providing some food for thought for this discussion.


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## robscastle (May 13, 2012)

Whoa that's not really good for the home.

The build up of heat in decomposing material is a natural occurring phenomenon, that is how weeds are killed in compost heaps, I think its over 70 deg plus!from memory (which kills seeds nuts etc) and then weed free compost is the result, so its not just confined to wood projects.

Grass as mentioned, and if you are curious and want to do some of your own research place hand full of lawn clippings in a plastic bag seal the top and it will eventually pop like a balloon.

NIt applies to non grass and wood too, now try a ball of steel wool wound around a thermometer and then place them into a glass jar filled with some water, seal the lid and watch the resultant rise in temperature as the steel wool decomposes.
Its not as dramatic as grass/wood and will not explode but the effect is there. Decomposition, (work) produces heat energy.

In the garden with sawdust and wood chips and the likes you should dig them into the soil at about a 25% ratio otherwise the natural chemicals in the wood may kill everything rather than promoted good growth, I think is the effect of a nitrogen layer forming in the timber.

As bigk said dust in lying in and around lighting is also a risk, especially if you have halogen lights, halogen run at about 200 deg and if there is dust on them you will smell burning as a pre warning.

In closing also don't forget also as you are working hot fine dust can explode in the presence of static electricity when friction is produced as it travels along its journey in the flexible ducting to the dust extractor.
Make sure effective grounding is in place to reduce the risk.

I think my drum sander is the most serious offender as it raises my hair as I move around the wood sanding it.


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## themelster (Feb 14, 2013)

Back in 2012, Wi. had sever drought. DNR was advising folks who had placed mulch all around their homes to move it away… after thinking about it, all your doing is creating a fire ring around your house. I now have stone all around vs mulch.


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## DennisD (May 7, 2009)

Wow! I have been putting cedar sawdust in the mulch bin… not any more.
Thanks


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## Henry6 (Nov 6, 2012)

That is a bad news hope you might haved fixed your house untill now,Hope you are protected this time from the reason that caused fire.


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## LogHomer (Jul 5, 2017)

This morning my wife woke me up at 8am yelling "We have a fire!" We are living in our Log home as we build it and it's about 90% complete. I run out of the bedroom and immediately see, through the front window, four foot high flames out on our covered 8' by 32' front deck. I put it out with the fire extinguisher and took stock of the damage. It was a clear day here in the NY Catskills and there was no obvious reason for a fire to have begun on a porch at the end of a dead end road. No electrical issues. No smokers in the vicinity for at least a full day. No oily rags. The 2' by 2' box of scrap wood from our chop saw and table saw was about half consumed by the fire and we chucked it over the railing to the ground 8' below. The gooey mass which was solidifying as it cooled down from a smoldering clump next to the scrap box was all that remained of the 5 gallon orange bucket from Home Depot. It was what I had been putting the sawdust from the saws in for the last month or so and had been nearly full. The only thing left was the metal handle now encased in a solid plastic blob sitting on top of several charred deck boards. This was a terrifying experience for wife and I and is what prompted this morning's research and these comments. Thanks for this site and be advised: compressed saw dust from mostly Eastern White Pine will spontaneously combust more readily than one could ever imagine.


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## firefighterontheside (Apr 26, 2013)

Yes sir, gotta keep it dry. Glad it wasn't any worse for you.


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## Carloz (Oct 12, 2016)

Now the neighbors can finally have some rest from endless vacuuming their floors because their pestering neighbor was dumping so much fine dust outside.


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## kelvancra (May 4, 2010)

Another thanks for the heads up. Glad your loss was minimal.


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## bbasiaga (Dec 8, 2012)

wow…crazy day!

I remember from working in grain processing that piles of corn germ, corn, and certain other corn byproducts (bran, gluten) would heat up and smolder. They were huge piles though, would not have thought 1' of sawdust could do it.

Brian


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## LogHomer (Jul 5, 2017)

Thanks for the support! And since this incident scattering sawdust around the property is the ONLY way I dispose of it and the only way I ever will; ashes-to-ashes and dust-to-dust.


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