Replies

1. 
   Guest_ | Jun 10, 1999 02:34am | #1

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   this is an australian site, they have had info in the past on charred members and structural integrity ( you may have to e-mail them ) click here

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   Guest_ | Jun 10, 1999 11:44pm | #2

   *'Tis true, I think, that wooden posts and beams above a certain size (6x6,8x8,??) qualify as fire resistant while steel beams can be weakened by high temperatures. But then steel beams are used in most commercial buildings of over 4 stories, and I haven't heard many tales of them collapsing from fires more readily than wooden structures. Of course, the steel beams have to be insulated and shielded to protect them in the case of fire (that is why you often see a white substance sprayed onto beams in high rise construction). If you boxed your steel beam with fire resistant materials to give at least a two hour fire resistance, you should be as well off, or better, than with wood. (Of course, you can increase the fire resistance of wood with various paints and treatments as well.)(Given a hot enough fire, even thick wood beams can burn completely. A couple of weeks ago we had an old grain elevator of about 100' burn completely to the ground in a couple of hours. However, I don't know just how thick the beams were originally...)

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   Guest_ | Jun 11, 1999 02:12am | #3

   *Hi Chris,IF the fire is hot enough to do damage to a steel beam, there won't be enough of your house to inspect afterwards anyways.Go with the product that fits your house design and span requirements and don't worry about the steel vs wood beam debate.As a volunteer fireman for 15 years, I was never in one that the beam made much difference.You have to remember that both are covered in drywall from underneath, on a second story floor, which means that they are already fire rated. The entire house would have to be engulfed in flames to heat the steel beams sufficiently to bend.If your still concerned, add another layer of drywall over it and don't let it keep you up at night.Gabe

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   mduval | Jun 14, 1999 09:46pm | #4

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   I'm no firefighter, just an Engineer. At approximately 1500 degrees F., steel will loose about 90 percent of its yield strength. I believe that a typical house fire reaches this temp.

   The question is, God forbid, if the house burns, how much you want left standing? Personally, I'm for total loss. I'd imagine it's a much smoother process dealing with the insurance companies.

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   Chris_River | Jun 14, 1999 09:46pm | #5

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   I am looking for information on the pros and cons of using dimensional or built-up wood for the main beam in a 32x56 two story house, versus a steel beam. Some time ago it was impressed upon me that steel is a lot faster to deform and collapse a house than wood, which will survive quite a bit of fire damage and still leave the house repairable. Can anyone tell me where I can find any facts or statistics to support or disprove this advice? Thanks for any assistance anyone can give me!