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Re: Plywood diaphragms

[Subject Prev][Subject Next][Thread Prev][Thread Next] I think the biggest problem you are going to have is making the roof
diaphragm work.  Using the typical building code distribution of story
forces, triangular force distribution, the roof force is going to be
significantly more than if the second floor was a wood diaphragm.  Some
people will argue that you have two different systems (flexible roof and
rigid 2nd floor) and you can separate the lateral loadings and not have to do
the triangular distribution.  You will probably be better off staying with a
concrete filled metal deck for the roof if possible, even if the construction
costs are more.  Makes it easier if you have to hang stuff from the roof in
the future.

Mike Cochran

In a message dated 2/23/2001 1:36:53 PM Pacific Standard Time,
ced(--nospam--at) writes:

Does anyone out there know if there is any code limitations to using a
plywood roof diaphragm with wood or light gauge metal trusses and a
structural steel frame?  I've never seen this done before or at least on a
building this size.  I have a two story 110' by 120' steel frame building
with a concrete slab on the second floor and light gauge metal or wood
trusses sheathed with plywood at the roof.  The roof is a 3:12 hip.

Any information would be appreciated.

Christopher E. Daniels
Larson Design Group
ced(--nospam--at) <mailto:ced(--nospam--at)>