beam vs. girder


Senior Member
French - France
Yet another technical question (construction)
Is there any difference between a beam and a girder.
For both I would say "poutre" in French.
But maybe a girder is only for steel structures ?
  • Guynouche

    Senior Member
    Yes, I tend to agree with you.
    You never hear of a "Timber Girder" but "Steel Girder" is commonly used


    Senior Member
    USA; American English
    I agree, too. Also that beams are generally referred to in smaller structures.

    A steel girder might hold up a bridge or be used in the construction of an office building, but a beam (generally of wood, but not necessarily) would usually be found supporting the roof of a house or apartment.


    Senior Member
    Canada anglais
    For a prestressed reinforced concrete element I shall use beam then. :tick:

    "There are some reinforced concrete beams in which the concrete is entirely in compression with tensile forces taken by steel tendons. These beams are known as prestressed concrete beams."

    PS: The link I provided isn't working. You could try googling "beam structure wikipedia." This entry has diagrams as well and there is a link to the same entry in French, "poutre" which may be helpful in determining if this is the appropriate term for your context.
    Last edited:


    Senior Member
    USA; American English
    That sounds like something for a large structure, and then I might use "girder." There ARE such things as concrete girders. It really depends on scale, as a girder is really just a large beam.

    This is from, defining a "concrete girder":

    A girder is a support beam used in construction. Girders often have an I beam cross section for strength, but may also have a box shape, Z shape or other forms. Girder is the term used to denote the main horizontal support of a structure which supports smaller beams. A girder is commonly used many times in the building of bridges, and planes.

    The difference in the vocabulary words can be very subtle, so you might want to do a Google search for beam and girder, maybe look at some images online, to see if you find something that resembles your particular beam -- or girder...