Truss roof - diaphragm

[frankettina]

Hi, i'm a structural engineer and i work in Belgium for a company that make Light Steel Frame building.
In the attachment you can see my last project. I have some doubt about the roof diaphragm.
I have OSB on top of the trusses and i would like to be sure that i can consider this type of roof as a diaphragm and that it can tranfer the horizontal load to the vertical element.

Hope i explained well my problem

thank you in advance!!

 

[DaveAtkins]

OSB works very well as a diaphragm.

It is difficult to comment on your design, because I don't know the specifics, but it does appear to me that you have some shear walls located near the center of the truss, not at the truss ends. Therefore, you need to provide diagonal members to transfer the diaphragm force from the OSB to the top of these shear walls, since the diaphragm might be several feet above the top of the shear walls.

DaveAtkins

 

[NorthCivil]

big ol' cantilevered diaghram there. run your numbers and KISS. i might consider some sort of bracing of the trusses at the shearwall to keep them all from doing a domino over.

 

[hokie66]

Providing a diaphragm at the ceiling level will KISS.