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reliabilityman

Main House Beams-What do you have? Metal or Composite

reliabilityman
16 years ago

I was surprised that when I have talked to contractors recently, most are using several composite boards fastened together to make house beams. I was assuming for my 1500 square footprint 2 story with basement that a steel beam would be used to span the 53' basment to support the 2 stories above, however the contractors I am interviewing say they would use laminates. Is this the norm now or the cheap way out??

What do you have holding up your house?

Comments (12)

  • mightyanvil
    16 years ago

    A beam spanning 53 ft. and carrying the load of the entire house would have to be a very large steel girder.

    Why would you span that far? Why wouldn't you span the shorter distance (28'?) Engineered wood beams could span 28' but if they carry the second floor load they would be huge. A couple of posts would save quite a bit of money.

    Engineered wood is not really a composite. It is wood laminated horizontally or laminated vertically. Horizontally laminated beams are called Laminated Veneer Lumber and can be nailed or bolted together. They are no as strong as steel so they will be deeper. They are rarely longer than 30 ft.

    You should talk to a structural engineer or an architect before talking to contractors.

  • mikeyvon
    16 years ago

    I have two 44' Glulams (laminated wood beams) that are 6"x24"s (pretty sure, might be 6"x20"s?? i cannot remember). They are supported at the ends by the foundation and we have 3 8x8" posts supporting them in between. So we are spanning 15' and they carry both floors and the roof load.

  • reliabilityman
    Original Author
    16 years ago

    mighty, I should explain further. I meant that the house will have support posts under the beam. I was not suggesting that one beam span the 53 feet without any supporting posts beneath it. I was just curious if the beams should be steel or laminates?

  • anthem
    16 years ago

    If LVL beams are properly engineered they are fine. I'm not sure you can say LVL beams (or PSL columns) are much cheaper than steel. They are certainly easier to work with which is why most residential builders will prefer them over steel. LVL beams engineered correctly can be cut and put into place. Steel requires a welder to come out (probably for a 1 hour job) and has much less flexibility in terms of changes.

    I've got places where I have steel I-beams and places where I have 18" LVL beams. Usually the place where you have the largest LVL beam is above the garage door span or where the main span of the house is.

  • sierraeast
    16 years ago

    Tripled 1-3/4" lvl's 16" wide by 22' long for the upper ridge, quadrupled 1-3/4" lvl's 18" wide by 28' for the mid span, Tripled 1-3/4" lvl's 12" wide by 28' for the loft support, quadrupled 1-3/4" lvl's 12" wide by 14' for the dormer rafters each side. All structural headers tripled 1-3/4" lvl's, stair stringers 1-3/4" by 12" lvl's. Under floor girders, doubled 1-3/4" x 9" lvl's w/post and piers 6' o.c. All glue nailed w/ 16's every 16"o.c three nails vertical except on the 9" girts. Not long after our framing, full width lvl's became available saving having to double, triple, quadruple, etc.

  • sierraeast
    16 years ago

    Left out all rafters w/ the exception of the master bedroom attic trusses are all 1-3/4" by 12" lvl's, the longest being over 28' supported by the 18" quadrupled lvl's.

  • mightyanvil
    16 years ago

    Steel is incredibly stiffer as well as stronger in bending & shear compared to wood of any kind.

    Also steel beam I shapes are more efficient than rectangular wood shapes.

    So, you will often want to use steel when size matters.

    The best material for short lightly loaded spans is usually determined by the material/fabrication cost and ease of installation rather than the structural characteristics of the material.

    Long and/or heavily loaded conditions can be spanned by smaller steel beams or larger wood beams. Obviously, wood beams would reach their practical limit in size well before steel beams.

    Often the choice of structural materials is determined by the design and configuration of the house especially if it has a ducted HVAC system.

    There are no simple rules of thumb for selecting wood vs steel.

  • sue36
    16 years ago

    We have three steel beams. This set-up was necessary because of the way the bearing walls are above. One beam on the right until about the middle of the house, then two beams on the left (shaped like =- ). The ones on the left have columns under them at the midpoints, the one on the right is a much shorter span and does not. We looked into LVLs but steel was shorter, making finishing the basement (if and when) easier.

    The welder charged $25 to weld the beams to the columns. Not sure why it was so cheap. Maybe it was $25 per column, still a deal.

  • rwj3933_verizon_net
    15 years ago

    I am looking at new home, and notice that in some homes, steel beams are used in the basement and in others, wood beams are being used. The contractors that I have spoken to say that the wooden beams are as good as steel. Others say the steel is better.
    What should I be asking for in the house that I would build?
    Is steel safer and stronger?
    Is wood as good as steel?
    Thanks for your help.

  • royking
    15 years ago

    I have a similar problem . I have a 28 foot span in my basement . there are 3 support posts . I want to remove one of the posts. My builder says he wants to replace the dimensional wood beam in that 14 foot span with a larger dimensional wood beam . I thought steel would be better and about the same price . (?) Would engineered wood be a better solution ? There are two floors above the basement . House built 2007 .

  • msm859
    15 years ago

    I made my whole house out of steel. I believe it gave me more design flexibility at less of a cost than having to worry about a lot of expensive glue lams.

  • Baird1fa_uregina_ca
    12 years ago

    Basically either will work. When designing my house the designer wanted to use 5-1/4" x 15" PSL beams. Basically osb beams. I wanted steel for supplier preference. My engineer calculated the size of beam I needed. With steel it became a W200x31 which is 210mm (8.25")x134mm (5.25") and weighs 31kg per meter. Steel will be smaller and lighter and capable of loner spans. But both will work. Talk to an engineer either way and they will calculate the proper size.