Replies

1. 
   BossHog | Feb 16, 2007 04:40pm | #1

   There has been all kinds of discussion about this over the years. I even did a thread about it once:

   http://forums.taunton.com/tp-breaktime/messages?msg=37987.1

   But is it a big deal? I'm not sure.

   I don't see I-joists as a threat to occupants. If the fire has progressed to that point the occupants won't be alive anyway. I have never yet head of a case where I-joists burned through and caused the deaths of any occupants.

   As for firefighters - I'd say yes, they CAN be a hazard in some cases. So what exactly should they do about it?

   My suggestion to fire departments I've talked to has been to give up the idea of risking lives to save structures. There's no point in riskign someone's life to try to stop a fire when the HO will likely bulldoze the place and start all over again anyway.

   I-joists aren't going to go away. Right nowe they're used in about 80% of new homes around here. Fire departments are going to ahve to find new ways of dealing with them.

   Did you hear about the fire at the circus? The heat was intense.
1. 
   bp21901 | Feb 16, 2007 05:14pm | #2

   Sorry 'bout the repeated topic, I didn't think to look around before posting or I would probably have let it pass."I don't see I-joists as a threat to occupants. If the fire has progressed to that point the occupants won't be alive anyway. "I don't necessarily agree with this, since the occupants could be away from the intense part of a fire holed up in a closed bathroom or bedroom. You could also have the other case where the fire is relatively small but it is the smoke inhalation that kills. With a fire it is hard to tell how deadly it is by looking. The firemen certainly don't assume everyone inside is dead already. If my child was in the burning building I wouldn't want them to assume that either.I agree with you that the beams are not going away. Like most things there is a learning curve and updates can be made to make them better. There is probably a semi-easy adjustment that could be made in the mfg of the beams to make them more fire retardant. I am sure the companies won't do this without a kick in the butt from either insurance companies, local codes or whatever requiring it. The mfg's would view it as an admission that the previous product was inferior and make them more vulnerable to a lawsuit. I also agree that a lot of the time they should just let the bldg burn down rather than send someone in to put it out. Are there any requirements for residential sprinklers in your area? I wonder if you get a break on insurance rates for having them installed, I've never looked into that.As an aside, there was a fire at a hardware store near here last week that they let burn down. They had to stop throwing water on it because of all the fertilizer there and they couldn't contain the runoff from going into a creek. Hadn't heard of that before.

   Edited 2/16/2007 9:15 am ET by bp21901

1. 
   highfigh | Feb 16, 2007 05:46pm | #3

   I'm sure they have been tested for the effects from fire- if someone googles for the testing labs in Steven's Point or Madison, WI, they probably have some links. Otherwise, the manufacturers have the same data.I know solid wood will char if it's exposed to fire or high temps but I kind of think that the glues will fail on these at some point. Either way, the occupants should bug out if there's a fire and the firefighters should stay out once the building in involved to a certain extent unless it's known that someone is in there. Screw the building, save the people and get out so the fire can be put out from the outside.
   "I cut this piece four times and it's still too short."

1. 
   BossHog | Feb 16, 2007 07:03pm | #6

   "I'm sure they have been tested for the effects from fire"

   They only have to be tested if they want a fire rating for a specific assembly. there are no minimum standards for residential fire ratings unless they're required by local building codes.
   Born free (my father's a doctor).

1. 
   highfigh | Feb 16, 2007 08:36pm | #11

   True, but the materials labs have tested just about every building material. It's non-profit- they do it all the time. Actually, it's part of the engineering department of the UW system and we pay for it with our taxes and the tuition.
   "I cut this piece four times and it's still too short."

2. 
   AllTrade | Feb 16, 2007 09:08pm | #12

   Really good fire alarms  is the key. Properly placed and maintained. Meaning replaced when they have met there time limits.

   Someone said it right before. There is less to burn through which is the main problem only a 1/2" thick the webbing and its gone! sheetrock will slow it down but nothing is full proof.

   Its easy to blame the ones who make it but they have just given us options. Just like everything else it comes down to us as individuals. There comes a time when its got nothing to do with the manufactor at all. If you can buy a blanket thats fire proof up to 5 min or one thats fire proof for 10 min and one cost $5 more dollars than the other, than its up to you as the buyer to make the choice not the manufactors. Perhaps code should require us sheetrocking them never leaving them exsposed but right now its up to you ? What's in your wallet???????????

2. 
   BossHog | Feb 16, 2007 06:59pm | #5

   Your theory about danger to occupants is only that - A theory. As I said, I've never heard of a case wher occupants were put in danger sue to I-joists. I've heard different views on residential sprinklers. Some say they reduce insurance rates. Others say they increase insurance rates because of the possibility of water damage from leaks. I've never asked an insurance agent to see what they say. And it may vary frmo one company to another.
   You can have no "right" that imposes an obligation upon someone else. [Walter Williams]

1. 
   bp21901 | Feb 16, 2007 07:19pm | #8

   I shoulda been more specific...my point was only to the second part of the quote about the occupants already being dead, not that the joists were going to kill them...sorry.I bet there are any number of additives that could be part of the glue formula. Heck even the stuff inside disposable diapers is fire retardant. Like you said, any added cost, no matter how small isn't going to be adaopted without being forced.

   Edited 2/16/2007 11:21 am ET by bp21901

1. 
   dovetail97128 | Feb 16, 2007 08:00pm | #9

   They tried that with plywood for roof decks some yrs back. The result over time was that there was a chemical reaction between the treatment and the glue and wood.
   Quite a number of Fire Fighters died finding out that the treatment caused catostrophic weakening of the assembly.
   My memory is at least 12 in R.I.(Can't remember for sure which state). My old man travelled from out of state to attend the funerals. An Entire roof collapsed from under them due to the failure of fire rated ply.
   Modern building materials and house furnishings have made firefighting much more dangerous in some ways than it was in the old days before better living thru chemistry.
   On the other hand buildings are much safer in other ways as well.

2. 
   dovetail97128 | Feb 16, 2007 08:04pm | #10

   Boss,
   In the county next to mine sprinklers are mandatory under some circumstances in residences.
   Distance from paved road, Distance from Hydrant, Sq. Ft. of house . are the criteria. Semi-rural county.
   No sprinklers = no permit.

3. 
   BossHog | Feb 16, 2007 07:15pm | #7

   "There is probably a semi-easy adjustment that could be made in the mfg of the beams to make them more fire retardant."

   Missed that comment on the first read.

   I seriously doubt there's any "adjustment" that could be made that would make them more fire resistant.

   I've heard suggestions before that they could be coated with something that might help. (I don't know what it would be) But I doubt anyone is going to want to pay for it. So I don't look for that to happen.
   It's a helluva start, being able to recognize what makes you happy. [Lucille Ball]

2. 
   Catskinner | Feb 17, 2007 03:19am | #13

   Boss, you are correct on all points.Before I became a construction worker I was a firefighter, worked as a lineman, a rescue specialist, rescue supervisor, and station captain. I'm a semester or two short on a degree in fire protection engineering, and have more than enough field experience to care less about the degree. As you can imagine, quite a bit of that education has to do with the effects of fire on buildings. The purpose of course is to be able to make a good decision as you roll up to a building. The decisions made during initial setup and attack are not usually subject to change, and you don't have much time to make them.So we pay a lot of attention to how building materials act in a fire.In my experience, properly installed drywall on a modern frame structure gives you a certain amount of protection for the framing, assuming an ordinary fuel load and no accelerants. That level of protection far exceeds anything I have ever seen a human being live through.The key here is to build to code (at a minimum) and do a good job. There is no single thing a builder can do that is more important for life safety. Equally important; smoke and CO alarms, properly installed and maintained.As an aside, the all-time worst are the old trailer homes. If you want to be afraid of fire, watch one of them burn.So as for a hazard to the occupants, I don't see it. By the time light wood framing is structurally compromised it's usually gotten hot enough that human survival is unlikely.As for a hazard to firefighters, I am equally unconcerned. Part of the rational decision to enter a building is an evaluation of the structural integrity on the basis of your observations. Professionals don't take risks so much as they minimize the hazards.Yes, I have gone into some ridiculously hot places (I've melted helmets. <G> But I knew what I was doing and why, and I am still here. If I thought a building collapse was imminent on the basis of my observation, education, and experience I would not do that, and I would not permit my crew to.So basically I think it's a non-issue.Now code compliance is another story. Get me going on that one some time . . .

1. 
   bp21901 | Feb 17, 2007 04:04am | #14

   Then it sounds like the only situation that could possibly be an issue is when they are used as first floor joists and there is no ceiling cover in the basement to provide protection from the flames. This seems to be what the fire dept. Lt. was indicating:"There's a possibility that this construction may have been involved in one firefighter fatality and a number of firefighter close calls," said Lt. Russ Davies from the Anne Arundel County Fire Department."The compromise of the integrity of the structure would make it more difficult for us to reach them and evacuate them from the property," Davies said. "The circumstances the firefighters have been seeing is they can sound the floor out. It seems to be stable, but with the plywood down and the carpet down, they don't see signs that these beams are failing and when you get the full weight of the firefighter and his gear, the floor fails and they fall to the floor below."

1. 
   Catskinner | Feb 17, 2007 08:11pm | #15

   I think that your case could be made with a high degree of confidence. I would regard uncovered wood I-joists as extraordinarily dangerous to firefighters.I have fallen through structurally unsound surfaces and I assure you that it is both somewhat surprising and unpleasant.

2. 
   renosteinke | Feb 16, 2007 05:48pm | #4

   I'm not so sure that they "burn faster" so much as 'there's less to burn.'

   Wood generally burns at the surface, and gradually loses strength as it is consumed. An I-joist has more surface area for the wood uses, which means that more is exposed to fire for ignition. Likewise, the very economy - using much less wood, for greater strength, than a solid piece of lumber means that it doesn't take long to burn through.

   Another factor might be one of coincidence; the newer I-joists are more likely to be surrounded by other stuff that burns -plastic pipe, plastic wire, etc.- and have much longer spans than an older building. (The longer span can help create a good draft - much as a taller chimney does).

   The usual proper construction methods ... fire stopping, enclosing with drywall, etc ... pretty much remove the joist from being a factor in fires.

   One point often overlooked is that the vast majority of fires originate in, and are fed by, the occupant's possessions. There is only so much that can be done, when the space is filled with highly flammable materials. Furniture, clothing, trash, carpet, wood paneling, even the varnishes used on wood tables have been described as "solid gasoline" when they burn.

3. 
   frenchy | Feb 17, 2007 09:45pm | #16

   bp21910.

    You need to look beyond what you see and consider what is happening,,.

     For exmple when a beam fails most likely it is not simply fire burned thru it.. rather what happens is the fire ignites the wood fibers which cause the "glue" that holds everything together to weaken.  at some point the "glue" fails and the fibers disassemble themselves..

      As the beam disassembles itself the scattered fibers present more edges to ignite..

     (sorry a little science here.  If you take a match to a chunk of wood you will have a hard time getting it to ignite due to it's mass which needs to be raised past the point of ignition..  However a wafer of wood is nothing but edge and therefore very quick to ignite)  all those burning edges raise the BTu's generated by the fire and  cause even more fibers to come apart and so on and so on etc..

       

1. 
   bp21901 | Feb 17, 2007 10:42pm | #17

   I don't think I am disagreeing with you at all. If prior posts indicated that, I didn't make them clear enough.