Well, I thought the title might go O.K., given the proximity to Christmas…………..(-:
We were cutting firewood out at the farm today And we generally burn the brush to get rid of it and keep warm.
While we were loading up the truck I got the bright idea of throwing in an I-joist sample. Just curious how it would act on a fire.
I know this isn’t even remotely close to a scientific test. I just wanted to see what would happen.
The first pic is just a few seconds after the piece was tossed in. These first four pics span somewhere between one and 2 minutes.
It’s a small world, but I wouldn’t want to have to paint it.
Replies
Starting here pith pic #5, you can see the edges have already caught.
By pic #6, the whole thing is charred.
In pic 7, the whole thing is burning.
Give me a few minutes, and I'll post the last 2.
Humpty Dumpty was pushed.
These are the last 2 pics. In #8, the thing is what I'd guess they call "Fully Engaged". It was not only burning quickly, but was putting out a lot of heat, too.
In pic #9 the OSB flange had broken in half just under the weight of the I-joist.
The total time from pic #1 to pic #9 was 4 minutes.
I didn't take any more pics after that. But by the time 6 or 7 minutes had passed, there was no trace of the I-joist.I used to go sunbbathing on the beach a lot - But people from Greenpeace kept trying to push me back into the water.
Good test. Do you have another small piece of I-joist and a small piece of 2x10. I'd like to see how they burn at the same time.
Joe Carola
Interesting series Boss.
Kinda makes the question of whether to go to 5/8's (or thicker) a non-issue...
Jon Blakemore
I've been getting training as a volunteer firefighter at the local department, and it's interesting to see the fire service perspective on the building industry. 'Innovations' like the I-joist, the lightweight steel roof truss, and the tightly-sealed building are incredibly dangerous in a fire, not to mention all of the plastic and petroleum-based possessions we all have these days. Neat photo series, and definitely test a chunk of 2x10 on the next round.
I've done a couple of presentations to fire departments on trusses and fires, and have a couple more scheduled. Sems to me there's a lot of misinformation from both sides of the issue out there.
Didn't think about taking a piece of 2X lumber along. And I didn't have a section of a truss to try out. Just grabbed the thing on a whim to see what would happen.
Keep in mind here that the fire was pretty hot when I threw the thing on. There was a heck of a bed of coals under there.
Still, I was surprised at how quickly it burned. Wasn't expecting that.My wife says if I go fishing one more time, she's going to leave me. I'm going to miss her.
A simple test that would be somewhat simulate real world would be to get a control flame, such as the burner from a turkey frier. Then use some metal sawhorses to a couple of test pieces over the flame. Put the flame off center and at center tie a concrete block to each one with some wire.
Boss,
Since the use of engineered lumber (and trusses) is not going to go away, I think your example highlights the need for appropriate fireproofing. Think of how many (at least where I live) newly constructed homes have 1st floors with exposed I-joists in the basement.
It may not be code, but a good idea none the less to slap up a layer of 5/8 drywall below, and to have some way to cheaply, but effectively fireproof a truss. Might have saved The Trade Centers from collapse with the new info that's coming out.
Jon
"Think of how many (at least where I live) newly constructed homes have 1st floors with exposed I-joists in the basement."
I wouldn't have much of a problem with drywall ceilings being required on I-joists. But currently no one is pushing for that. (At least as far as I know)
"... and to have some way to cheaply, but effectively fireproof a truss."
Are you talking roof trusses or floors?
On floor trusses, I think the drywall ceiling would be a big improvement. But some partitioning would also be a good idea.
If you're talking roof trusses, I don't agree. I haven't seen any evidence that roof trusses pose a serious risk in single family structures. (Multi-family and commercial is a whole different story)I've run out of sick days, so I am calling in dead.
i have an old buddy who is a sprinkler fitter, and i remember him tellin me about the I joists burning like that maybe 10 years ago, in answer to joe's post, I'm sure my buddy had precise figures, but the solid lumber lasts way longer before it was weakened to the point to collapse. not long at all with I joists.
fire sprinklers save lives. ya they cost money and are ugly but they will put the fire out most ricky-tik
I do remember an industry-sponsored burn thread we had referenced on the forum several years ago...maybe back in '97.
T'was a thread devoted to TJI platforms vs stick lumber, cells-packed walls vs FG.
I don't recall any CDX vs OSB comparisons.
I don't remember which industry sponsored it.
I don't remember...very much...where's my coffee...
"I haven't seen any evidence that roof trusses pose a serious risk in single family structures."
Boss,
To a certain extent, I agree with you. BUT, about 7 years ago, my next door neighbor's house burned down. At 5:00am in the middle of winter after a snow fall, we were awoken to the sound of banging on our front door. (passerby stopped) At that time the house was ~1% engulfed. Within two minutes the fire spread outside from the wall of the house through to the eaves of the (attached) garage (garage was completely drywalled) and set the trusses and roof sheathing on fire. The garage collapsed just as the fire trucks showed up less than ten minutes later. The resulting collapse cased the fire to quickly enter the house structure, and caused the house to be a near total loss. They saved ~1/3, but in the end, it cost more to rebuild than knock it down and start clean.
I have time sequence photo's of the entire event, but can't find them just now. (Insurance company really liked them as they kept my originals).
Oh, and BTW, nobody was home at the time.
Jon
Edited 12/22/2003 3:47:15 PM ET by WorkshopJon
Edited 12/22/2003 3:49:52 PM ET by WorkshopJon
Boss,
I see you read my post with no comment. As I find your comments educational to say the least........
My point was that drywalling the inside of a structure can make a huge difference, but fire can also enter through eves, effectively bypassing the fireproofing. It takes virtually no time at all for a hot fire to burn through a 2 x 4 truss once the fire makes its way in there, as evidence by the quick destruction of my neighbors house.
Jon
I didn't respond to your comments because I've covered that ground several times here in the past.
In the case you mentioned, the trusses collapsed fairly quickly. But it's hard to say exactly how fast, since we don't know when the fire started and how long it had been burning. The fire could have been smoldering in the attic for hours.
We also don't know if there was stuff stored in the truss space that the trusses weren't designed to hold. Or some of the trusses could have been cut for an attic stair, or something like that.
No one incident can be used to say that trusses are or aren't "safe" in a fire. Since every fire and every house is different, the only thing I can go one is historical data on fires.
I've been interested in this subject for quite some time, and have read a lot of incident reports on fires where trusses were involved. This is what I've learned:
1. I have never heard of a case where occupants of a house were prevented from escaping the structure because of trusses failing.
2. I don't know of a single incident where firefighters were killed by falling trusses in a single family structure. (I've heard it happened once in California, but have never been able to confirm it)
3. In very fire where trusses and fatalities were involved, there were other circumstances that contributed to the deaths.
Based on the information I've seen, I don't believe trusses in single family structures pose a great danger to anyone. If you want to get into commercial buildings and multi-family then there are things to watch out for.
Honestly, this is one of my pet peeves with both the fire service AND the truss industry. There's a lot of finger pointing and accusations from both sides. But it seems to me that no one is trying to figure out exactly what kinds of trusses/situations pose the greatest dangers and what to do about them. I'd like to see that change.When all else fails, read the instructions.
"I didn't respond to your comments because I've covered that ground several times here in the past."
Boss,
Sorry for the delayed response. I was out of town for the holidays and swamped at work.
Based on the title of the thread you started, and your first post, I thought that you actually wanted to discuss the flamibility of engineered structural building components.
Not to get in a "flame" (LOL) over this with you, but I think that it is just common sense that a truss built of 2x4 mtrl is going to fail quicker than the 2x10 or 2x12 rafter and ceiling joists they would replace in a traditionally framed (older?) house. How much quicker??????? as you point out, no hard data on the one, (according to you) AND many things could mitigate and change the equation.
Personally, I think truss construction is THE way to go, my only "pet peeve" with it is that the widespread use of [2x4] trusses has changed house design to the point of making certain "classic" styles somewhat economically obsolete.
Jon
"... I thought that you actually wanted to discuss the flamibility of engineered structural building components."
Well, I'm not against discussing it. I was just curious how the I-joist would do in a fire, and thought everybody else would be too.
"Personally, I think truss construction is THE way to go, my only "pet peeve" with it is that the widespread use of [2x4] trusses has changed house design to the point of making certain "classic" styles somewhat economically obsolete."
Just curious - What "classic" styles are you talking about?The trouble with doing something right the first time is that nobody appreciates how difficult it was.
"Just curious - What "classic" styles are you talking about?"
Boss,
The traditional 1 1/2 story cape comes to mind, as well as homes that were built with "attics" that were in future times easily converted to extra rooms.
Jon
Edit: Have to say, ....your tag line, ain't that the truth. Good one.
Edited 12/31/2003 10:30:48 AM ET by WorkshopJon
Trusses designed with open center areas capable of supporting full floor loads are commonplace. This allows for almost any 1 1/2 story configuration, including many classic styles....that's not a mistake, it's rustic
Jeff,
Very true, BUT it costs not that much more to add a second (full story with a 2x4 truss roof vs. going with "attic" style trusses. One of the reasons (at least where I live) you so rarely see them used.
Instances where you see them are when zoning restricts the height of a structure, and people are maximizing the square footage of the building.
Jon
Yes, but trusses are not the reason houses with actual architectural effort are no longer common. A perceived need for a 5,000sf vinyl boxes is to blame. ...that's not a mistake, it's rustic
"A perceived need for a 5,000sf vinyl boxes is to blame."
Jeff,
NO, NO ,NO...... A perceived need for a 5,000sf vinyl box THAT LOOKS LIKE A 10,000SF BOX. Couldn't help myself there.
Jon
I was just at a nice new vinyl box that a couple we met during lamaze class bought 6 months ago. The lot is along a busy road and under 1/4 acre (a variance so common in Northern NJ I don't see the of having a minimum space zoning requirement) facing the local retention pond. The upstairs was so huge, they could not hear their daughter crying two rooms away. They also have an obvious bathroom leak above the kitchen counter and there are so many nail pops in the living room ceiling, it looks like an intentional design....that's not a mistake, it's rustic
Jon
In the back of my mind I think........The top and bottom of an I joist is basically a 2x3....Once that burns the whole house is history...So aren't we talking a burnt 2x3 or 4 rather than a solid 2x10 or whatever?
I think the test should be with a common load above it such as couches, tables and bearing partitions above to see the extent of pressure in Dante's Infurno.
Soon to come: I-joists made of steel with 2x3's fastened to the top of em' with nailers in the middle if necessary....Carbide blade comes with each $1000 order..Geezzzzzz why'd I give that idea away??????
Be a fire extinguisher
andy
PS..Does the wife "still" like you? lolMy life is my practice!
http://CLIFFORDRENOVATIONS.COM
"PS..Does the wife "still" like you? lol"
Andy,
Geez, I had to sacrifice my long planned visit out to see you for her, so she better. (let's just say diamond studs were at the top of her "wish list") and I know an honest jeweler in NYC. Actually, the only time I spent on LI was at the airport, and with all the relatives in (including from Europe), just not enough time.
BTW, Best holiday wishes to you and your family,
Jon
You know this, probably better than I do. I find it interesting that once the wafer board web looses strength, doesn't even need to burn as heating alone can weaken it, you go from a relatively strong and stiff I-beam to two 2 by 2s. Not the sort of thing a fireman wants to jitterbug out on or, even worse, stand underneath.
That's why I used TJIs in my own house.
Survival of the fittest. Get out or die.
And once you're out, the house will quickly collapse, eliminating the temptation to go back in to get my prized collection of junk mail envelopes.
TJIs are indeed a good reason to use 5/8ths rock.
From:
Mongo
Dec-20 10:30 pm
To:
4Lorn1
(9 of 15)
37987.9 in reply to 37987.8
That's why I used TJIs in my own house.
Survival of the fittest. Get out or die.
There is another good point in that the insurance will have to total. One of these days they are going to figgure that out .
Tim Mooney
Tim, in the KY residential building code there is a section that say floor trusses must have one hour rated partition in them every 1000 sq. ft. when there is habitable space below them. I can't seem to find any such restrictions for I-joist. The fire wall partitions are eleminated even for floor trusses when there is a drop ceiling below them.....go figure?
Does anyone know of code restrictions for I-joist? Maybe there just haven't been enough catastrophic failures of I-joist in fires to bring about code changes yet. Insurance companies and the NFPA wiil drive them, when and if it happens.
Dave
"Does anyone know of code restrictions for I-joist? Maybe there just haven't been enough catastrophic failures of I-joist in fires to bring about code changes yet"
I haven't seen any. But remember that I-joists are a relatively new development in residential construction. Ten years ago they had maybe a 10% market share around here. Now they're up around 80% or more.
"The fire wall partitions are eleminated even for floor trusses when there is a drop ceiling below them.....go figure?"
That's probably because the dropped ceiling restricts the supply of air to a fire in a floor system.Beauty is only skin deep. But ugly goes all the way to the bone.
Moved up to 80 percent from 20 percent. Give the insurance companies time . They are already giving discounts on concrete siding as of 1 year ago.
Tim Mooney
"There is another good point in that the insurance will have to total. One of these days they are going to figgure that out."
I don't think that is going to make that much difference in insurance rates.
This is just from what little I see from stories in the paper, TV, etc and no collection of statistics.
But it seems that you either have a fire contained to a room, a cooking fire, smoking and couch, heater in bedroom, etc. And with typical construction and use of DW that is contained to that area, but enough smoke and water damage is done that remainder of the house that there is a significant loss.
Or the fire get outside that room or starts outside a finished room, such as an atic or basement and then it become whole house and is largely a tear down anyway.
Then figure out what all the cost are that are not fire related, water damage, wind damage, liability and operating overhead.
once the wafer board web looses strength, doesn't even need to burn......
I've learned, by repairing many pieces of furniture, that almost any glue can be softened by using heat. With most glues, heat form a nearby lightbulb is sufficient to compromise the strength of the joint. It doesn't just dry out the wood, it actually melts the glue.
And of course, the web in an I-joist is nothing if it loses its glue. Same with OSB roof decking.
Pray for the firefighters.
Vast projects should not be founded on half vast ideas.
Didn't your mother teach you not to play with fire?
Yeah, but gasoline and matches are fun!
Regards,
Tim
I was the kid who stole the little strips of magnesium from science class just because the teacher said you would never want to burn them... Thank god that there are some things we do grow out of...
Matt
Edited 12/21/2003 8:34:17 AM ET by DIRISHINME
I feel better about what I experienced last week. I removed a short section of Log wall between a door and a window, about 3'. The second log up from the sill was about 7" thick and 12" high and TOTALLY hollow from termites it was eaten so that there was a 1/2" of good wood on each face and the rest was a honeycomb of channels and frass. I threw it on our burn pile,( it was blazing away.).and to my suprise it took a long time to actually start burning and quite a while before it was gone.
I had been thinking of R and R ing some of the worst, but even that bad they still have a lot more integrity then our newer and improved products.
I'll bet that if that hunk O' I-Joist had a few holes in the web like for wireing and pipes it would have parted even faster.
You grew out of it? Oh well...about the only thing I've ever grown out of is clothes.
Then you never did the powered aluminum/powered iron (thermite)?
Regards,
Tim Ruttan
Powdered aluminum and powdered iron oxide, not powdered iron. Very difficult to get it going- takes an oxy-acetylene torch at minimum- doubt a propane torch would even make it sneeze. Once it's going, the redox reaction yields white-hot molten iron- melts through any refractory container you might have laying around. Definitely not something you want to toy with...
When I was in college I had a friend who was a volunteer fireman. They got 5 pounds of magnesium shavings from a company to use for training. They only used half and he gave me the rest. We went camping and I dumped the bag on the campfire. We were blinded for a good 15 minutes.
This reminds me of a conversation I had at the local blues fest with the sound guy. I had been helping put tarps around his PA system because of one of those freak 15 minute drizzle rain storms. I asked him why the speakers needed to be covered for what to me seemed just like a mist. He responded be telling me that all manufactures of very large speakers use water solvable glue. So even a light misting can ruin a 1500 dollar speaker. Why would they use a water solvable glue on the cones? How does that make it easy for anyone? With that kind of glue a outdoor show in anyplace hummid in the summer would be slowly destroying the speakers over time.
I was at a drunken barn gathering a few years ago and someone threw a few pieces of OSB into one of those southwestern clay fireplaces, and the thing exploded, it hadbeen fine for years before. Seems to me like people could come up with some better idea's for common things like fire,water, and ice. Heck, I've got some why don't they call me?
Jason
High end speaker manufacturers use whatever gives them the best sound. Depending on the design, some of them used a very rigid, brittle glue to give the best control over the flexing of the cone (if I remember correctly - it has been along time since I followed this stuff...).
I thought my mother said fire was o.k. ... if you are a professional.
But not with gun powder... that's another story.
Ron
Thanks...you saved me a lot of time.
I was saying to my helper Adil just the other day that I was going to throw some scrap I Joists into my fireplace cause I was curious.
Hope you'll have done the solid wood v/s I Joists by the time I get back from skiing Thursday.....oh yeh, and if you happen to have some Advantech and CDX that'd be interesting too...see what you got yourself into.....lol.
Its a good service you're doing actually!! Thank you
FHB aught to post some of those pic!!!
Wish your family a healthy and happy Xmas from me and Katrina and the whole Clifford tribe.
BE well
andy
My life is my practice!
http://CLIFFORDRENOVATIONS.COM
"Hope you'll have done the solid wood v/s I Joists by the time I get back from skiing Thursday"
Don't hold yer breath. With the holidays and all, we won't be cutting wood again anytime soon.
"FHB aught to post some of those pic!!!"
You'll have to talk to Mr. Engle about that. But I'd prefer if they publish anything that it's done a little more scientifically than my little experiment.Man is the best computer we can put aboard a spacecraft... and the only one that can be mass produced with unskilled labor. [Wernher von Braun]
Boss - Sso you're the one burning a hole in the ozone. Yer not supposed to burn any wood that is treated or has glue in it.
Now don't go burning any more glue OK?
Hope you didn't cook any Smores over that fire.............
I'm guessing a 2x would burn much slower unless it was full of pitch.
Thanks for the pictures, they warmed up my cold hands........:-)
"Rather be a hammer than a nail"
Bob
I've got some 12x12 cut offs left both black walnut and white oak, anybody want to come and take some pictures of those burning?
Pictures? To capture the full consumption of those chunks of wood I'm thinking more like a movie - epic movie - long epic movie...
With 12x12 Black Walnut and White Oak timbers, I'm thinking your timber frame will hold up structurally in a fire longer than a steel I beam structure would.Kevin Halliburton
"I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity." - I.M. Pei -
Y'all that really wanna see something burn, do this: After Christmas, tote the now-dried out tree out of your living room, and throw it on the coals of a good hot brush fire---the darn thing will almost explode into flame before you can even draw back. Did this a few years ago, and haven't put a "live" tree in the house since.
Ever witness a Prairie burning?
There are some folks around here (SE MN) who cultivate native prairie grass...Big Bluestem and such...that needs to be burned off every year or two to keep competition down. Seems that happened naturally every once in awhile back in the days of virgin prairie, and the grass species that are desirable for a prairie restoration these days had evolved with deep roots so they would benefit from a good fire every now and then.
So there is this non-profit group that goes around with a big tank of water in a pickup with a gasoline pump, a few back back sprayers, and some shovels, to supply other volunteers to help do these burnings.
I volunteered to man a shovel this spring on a nieghbors plot. They set a back fire to protect anything that needs it, then fire up the big patch. Holy Cow! Faster than gasoline, flames 25 - 30 feet in the air.
Town where I used to live, every year the fire dept collects the Christmas trees, and has a big bonfire at night, with hot chocolate for the kids, skating on the pond, all that stuff. It's a great community event.
You are correct. A timber under typical house fire temperatures will develop a char coating that will protect the wood and last long after rolled steel sections begin to warp....that's not a mistake, it's rustic
Someone do this with a propane tank, I always wanted to see what would happen. I've done it with a 12 pack of Miester Brau, but not propane.
The only danger that I see from the method I used to build my house is the difficulty it would take to convince a firefighter to enter the building after it had been burning for a bit..
Used to tradional stick framing techniques few fire fighters will enter a burning building unless human life is at stake prefering to stand off and contain..
It's really quite reasonable logic since few homes could burn for more than 15 to 30 minutes without being totaled.
With the construction technique used here I believe that the fire could burn for a considerable time and still the house be repairable.. For example the factory that sells the SIPs has a movie of a fire that burned in the corner of a SIP for an hour with only a slight tempurature raise on the outside of the SIP..
while the wood flooring and other stuff could burn in the house it is certainly possible for a fire to start, yet I question if much structural damage would occur..
PS I tried to burn a 12x12 chunk in the fire place, it took a lot of kindling and over a week before it was gone!
Edited 12/25/2003 4:26:40 PM ET by frenchy
You need a mother in law room in the middle of the house .
Luckily for me she's been taking a dirt nap for quite a while now...;-)