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REPOST: Steel Lintel Bearing on Masonry

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Dave,

(If at first you do not receive a response, ask, ask again <G>.)

You ask some very valid questions about lintel support.  Since you have asked
for "personal opinions," I will offer mine.

I think that high edge loading due to lintel deflection is a greater cause of
distress at lintel supports than thermal expansion and contraction is.
Therefore, I typically provide a bearing plate below the lintel with the
bearing plate set back 1" - 1.5" (or so) from the opening on longer lintel
spans.  I also place a note on the drawing that the bed joint between the
plate and the opening is not to contain mortar.

It is very difficult, nigh impossible, for a lintel to move independent of
the masonry wall unless you can figure out a way for the lintel to move
independent of the masonry *above* the lintel as well as below the lintel.
Any thermal movement of the lintel different from the wall is going to have
the wall move.  Any thermal movement of the wall different from the lintel is
going to have the lintel resisting the wall movement.  In addition to being
prevented by the required extension of opening reinforcing, any vertical
joint above the lintel at the end of the lintel will prevent arching action
of the masonry.  I will typically provide hairpin horizontal reinforcing
around lintel anchor bolts or vertical reinforcing at the supports.  I also
like to put expansion joints in the masonry walls about 2'-8" back from the
opening.  CMU walls with brick facing would need to have expansion joints in
both materials at the same location.  (Exception:  Where fire resistive
separation is required, specialized offset expansion joints need to be
detailed.)

HTH

A. Roger Turk, P.E.(Structural)
Tucson, Arizona

Dave Nuttall wrote:

. > This is a repost of an earlier listing to which only 1 person initially
. > responded.  This is a topic which I am hoping can be further discussed.

. > I would still like to know what the various opinions are regarding the
. > bearing of a steel lintel on a masonry wall.

. > The typical lintel in question consists of a W section with a plate below
. > spanning somewhere between 6' and 30'.

. > Besides calculating the required bearing length, is there a preferred
. > method of anchorage?

. > Should the lintel truly be anchored to the masonry by welding  it to a
. > bearing plate, or should the lintel have provisions to move slightly so as
. > not to produce fixity?

. > What complications occur by fixity if the lintel is supporting a cavity
. > wall, where the brick wants to expand, and the cmu backup wants to
. > contract, but the lintel is only bearing on the cmu?

. > Does one method produce a different expansion joint & control joint layout
. > over another method?

. > I would also like to know the various details and configurations of the
. > different cavity wall lintels used by my peers.

. > Your opinions are appreciated,

. > Dave Nuttall, P.E.
. > Green Bay, WI

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