I have always designed for LL + Brick Load with deflection criteria of
L/700. A lot of times the Dead Load will all ready be on the beam so that
deflection doesn't come into play.
You say you are using the Hambro joist system. That system scares me as if I
recall the slab has no decking and the concrete is only about 3" thick. What
happens if the slab cracks. You lose your diaphragm capabilities. Hambro
will not guarantee that the slab will not crack.
From: David Handy <dhandy(--nospam--at)trg.ca>
Subject: brick veneer support deflection
Date: Mon, 24 Jan 2000 19:15:29 -0500
What values do you use for meeting deflection requirements when supporting
brick veneer at every floor. For example I have a building that use cast in
lintel angle wedge inserts. There is a 3" concrete slab for the floors that
is composite with the joists (HAMBRO). At the perimeter I am planning on a
steel beam with the slab thickened to 8" to provide enough concrete for the
anchors. This beam supports only a small strip of floor where parallel to
the joists and supports a 10' trib of floor where perpendicular. The shelf
angle at the edge of the slab supports about 12' of brick at each floor.
I have typically used L/720 for the beams using the live load plus half of
the weight of the brick wall as the means for evaluating the deflection. I
know that many would use just the live load and maybe even a less strict
L/???. What do you think?
David Handy, P.Eng