Re: Wood Joist to Steel Beam connection

Discussion in 'Building Construction' started by JD, Sep 18, 2003.

  1. JD

    JD Guest

    Jason McClendon <> wrote in message
    news:...
    > Is there a standard connection detail for connecting a 2x joist to a
    > steel W shape beam. I'd like to avoid welding if possible. Hangers are
    > O.K. I've read that drilling holes in that top flange is a no-no as it
    > undermines the strength of the beam. Is that so?


    Wood plates are often attached to the top flange with through bolts or
    welded studs.
    JD, Sep 18, 2003
    #1
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  2. JD

    Ralph Hertle Guest

    JD:

    Use steel clips that bear on the underside of the flange and that are
    through bolted to the wood plate on the steel beam. The wood is wider
    than the steel beam.

    I described this on a post on A.B.C several months ago, and I gave a
    link to the manufacturer.

    Flange drilling weakens the beam in a critical area, the flange, and
    stresses are localized at the holes. One might as well buy a narrower
    steel beam and save the money.

    In critical structures you would not weld to the flange due to the
    possible modification of the steel. Where there is sufficient strength
    welding would be acceptable, and would be far better than drilling.

    Ralph Hertle
    _______________________________




    JD wrote:
    > Jason McClendon <> wrote in message
    > news:...
    >
    >>Is there a standard connection detail for connecting a 2x joist to a
    >>steel W shape beam. I'd like to avoid welding if possible. Hangers are
    >>O.K. I've read that drilling holes in that top flange is a no-no as it
    >>undermines the strength of the beam. Is that so?

    >
    >
    > Wood plates are often attached to the top flange with through bolts or
    > welded studs.
    >
    >
    Ralph Hertle, Sep 19, 2003
    #2
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  3. "Ralph Hertle" <> wrote in message
    news:...
    > JD:
    >
    > Use steel clips that bear on the underside of the flange and that are
    > through bolted to the wood plate on the steel beam. The wood is wider
    > than the steel beam.
    >
    > I described this on a post on A.B.C several months ago, and I gave a
    > link to the manufacturer.
    >
    > Flange drilling weakens the beam in a critical area, the flange, and
    > stresses are localized at the holes. One might as well buy a narrower
    > steel beam and save the money.
    >
    > In critical structures you would not weld to the flange due to the
    > possible modification of the steel.


    Ralph critical connections on steel products are made by welding every day.
    From aircraft to high pressure piping to pressure vessels to bridges to
    buildings. Flanges and webs.

    JTMcC.




    Where there is sufficient strength
    > welding would be acceptable, and would be far better than drilling.
    >
    > Ralph Hertle
    > _______________________________
    >
    >
    >
    >
    > JD wrote:
    > > Jason McClendon <> wrote in message
    > > news:...
    > >
    > >>Is there a standard connection detail for connecting a 2x joist to a
    > >>steel W shape beam. I'd like to avoid welding if possible. Hangers are
    > >>O.K. I've read that drilling holes in that top flange is a no-no as it
    > >>undermines the strength of the beam. Is that so?

    > >
    > >
    > > Wood plates are often attached to the top flange with through bolts or
    > > welded studs.
    > >
    > >

    >
    John T. McCracken, Sep 19, 2003
    #3
  4. JD

    Ralph Hertle Guest

    John T. McCracken wrote:
    >
    > Ralph critical connections on steel products are made by welding every day.
    > From aircraft to high pressure piping to pressure vessels to bridges to
    > buildings. Flanges and webs.
    >
    > JTMcC.




    John:

    Of course you are totally right.

    I think that you are referring to the types of welded joints that are
    structurally engineered in the context of proper metallurgy and welding
    science.

    I failed to clearly state that in structures that are made of lesser
    metals, or that have too much welding, the structure of the metal in the
    beam could be altered, be weakened or have internal stresses at the
    welds that could lead to crack propagation. I would add that a
    structural engineer should be consulted for more information on the
    design of all connections as well as the engineering design of the beam.

    Ralph Hertle
    Ralph Hertle, Sep 19, 2003
    #4
  5. JD

    Ralph Hertle Guest

    Dan:

    Please don't think for a minute that I am opposed to your considerable
    knowledge and experience. Nor do I doubt your sincerity and honesty.

    I believe that based on my limited engineering knowledge of how beams
    function, that some courses in statics, strength of materials, and steel
    frame structure would be of great interest to you. A combination of the
    strength calculations and the real world of welded steel frame
    fabrication is the ideal that most of us would hope to achieve.

    I know some about the engineering principles involved, and I wish that I
    knew what you have learned about steel construction.

    Regarding the holes, the ones that you made probably did not remove
    enough material to compromise the strength of the beams, and there was
    probably a sufficient strength safety factor designed into the beam. All
    holes in the flanges of a conventional W.F. beam will weaken the beam to
    some extent. Even though the beam does not break there will be a
    measurably greater deflection. Also, the maximum load carrying capacity
    will be less after holes are drilled in the flanges. A calculation using
    actual values will tell what the increase in deflection under loading or
    the maximum possible loading will be.

    Thanks for your reply.

    Ralph Hertle




    Dan wrote:
    > Ralph,
    >
    > After 24+ years of industrial/commercial construction as a Union Ironworker,
    > (that would be me),
    >
    > 1. and having "drilled" one hell of a lot of holes in that time,
    > (top/bottom/middle)
    > 2. as well as welding damn near every connection type you can dream up,
    > (I've been an AWS certified welder Tig-Mig-stick for 20+ years),
    >
    > I do believe when I made the statement, "I'd find it darn hard to believe
    > about drilling a few holes in a top flange except for a few rare occasions."
    > I can back it up. And YOUR experience/expertise would be............?
    >
    > Dan
    >
    >
    >
    >
    > -----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
    > http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
    > -----== Over 100,000 Newsgroups - 19 Different Servers! =-----
    Ralph Hertle, Sep 21, 2003
    #5
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