Hi Stewart Jeske, P.E. with JEI Structural
Engineering. I’m going to talk a little
bit today about the importance of being
able to secure reinforcing inside of
mullions. Vertical mullions and horizontal
mullions so that it is engaging the mullion
where it needs to be for loads. The first
area that I want to talk about a little
bit is horizontal mullions and
reinforcing that we would put inside to
reinforce. Horizontal mullions so
this is a solid tubular extruded
horizontal mullion. So if we had to
reinforce this say for a 10-foot opening
or a 12-foot opening or even greater.
What we would need is some reinforcing
that goes inside of it. Now here’s the
importance of securing whatever we use.
If reinforcing a tubular
reinforcing out of steel or something
like that we want to make sure it just
doesn’t sit there on the bottom of the
mullion because if it just sits there on
the bottom of the mullion it’s creating
additional load to the aluminum mullion.
It takes a long time and a lot of
deflection for it to actually engage and
support the aluminum mullion so it’s really
important for us to be able to fasten at
the ends of the horizontal mullion and
also, the center of the horizontal mullion
to make sure that this reinforcing is
always at the top part of the horizontal
mullion and it’s actually doing the work
to keep thealuminum which is
the weaker part from deflecting downward.
That’s the important part we
actually, had a case we’re out in the
field we had several different mullions
that were reinforced over a tall wall
and it was over an entry area and they
were seeing a lot of
deflection and whatever we asked in the
field. We asked them you know how was
this secured how was the reinforcing
secured inside the mullion and they
actually, indicated it wasn’t it was
actually, just setting in there and so it
was actually causing additional
deflection of the horizontal mullions. So
that’s one item that I wanted to talk
about. The other is with a horizontal
mullion. If we have an infill plate as is
seen right here this is a bottom infill
plate it’s important that we do not load
that infill plate or shim off of that
infill plate because it may cause too
much load for that infill plate to be
supported. In this case we wouldn’t be
able to shim the thethis
reinforcing into place we would need to
have connections that actually connect
it either through the tongue through the
tongue into the into the structural
shape or we would have to have some type of connections in through the top part
to be able to actually engage that
reinforcing inside of the horizontal but
it’s very important that we do not load
the infill plate because it’s just a
snap in plate and we don’t want to
overload that snap in plate so that’s
horizontal mullion and what we will see
in terms of securing the reinforcing
inside of that the other item that I
wanted to talk a little bit about today
that we’ve kind of found out in a field
that’s important is security reinforcing
inside of vertical mullion as well the
importance of that is if we if we
have some type of a reinforcing that
might be a bent plate something like
this in the shape of a channel and we
try to put it inside of the vertical
mullion for reinforcing the vertical
mullion actually has a lot of distance in
there that it can actually deflect back
and forth before it actually engages in
it and so the appropriate thing that we
to do with this reinforcing to be able
to engage it and make sure that it moves
with the wind and that there’s not
noises in the system is that we would
either have screws that actually engage
this at the horizontals where the
horizontals go through or again we would
need to shim this reinforcing into place
to make sure that there’s shims at the
ends and in the middle so that it
adequately engages that reinforcing and
make sure that it does not
deflect until it reaches the reinforcing
one of the items that we experienced in
a project with reinforcing vertical
mullion was where we had some very long
and tall runs vertical tubular mullion
and we had some type of a reinforcing
that was a bent c channel and that was
supposed to be inside of it and we
actually, received reports from
inspectors in the field that this this
channel was not straight it was actually
bowed and out of place inside of the
vertical mullion they were hat somehow
they were able to gain access to the
inside look and see what was going on
and so it was not appropriately shimmed
or attached at the at the horizontal mullions so that very important for reinforcing to be adequately connected to the mullion at the ends and at the horizontal mullions.