bar grating

[nitnelion]

Can bar grating be used as a structural diaphragm?

 

[nuche1973]

I don't think so. Are you refering to bar grating used as a walking platform?

 

[nitnelion]

Yes. Its 1 1/2" x 3/16" galvanized bar grating. My problem is that I have a large elevated platform (200' x 100') with bar joists at 4'-0" o.c. The bar grating sits on top and is clipped to the top chord of the joists. The lateral bracing is at the perimeter of the platform. I'd like to make the grating somehow act as a diaphragm and get the forces to the perimeter. Do I have any other options? Thanks

 

[JStephen]

The bolting used to hold grating down isn't really intended to carry other loads through the grating. Also, bolted grating can be removed when necessary for access or painting. I would assume the structure needed to be stable without any contribution from the grating.

 

[nitnelion]

Would welding flat 1/4" x 4" bars to the top of the bar joists be a good solution? The grating wouldn't be exatly level though. The only other option I am thinking about would be creating a horizontal truss system under the joists out of tee's or angles.

 

[spats]

Not only can bar grating NOT be used as a diaphragm, it generally should not be considered to provide lateral support for your beams/joists.

 

[civilperson]

I disagree with spats opinion. Bar grating attached at three locations per panel width per end has sufficient stiffness to replace diagonal braces, produce diaphragm action for unit panel, (not multiple panels with gaps between), and for top flange bracing if carried to a rigid member at the perimeter, (not another joist or beam). Panels designed to be removed for easy access to space below are questionable for the substitution of bracing or diaphragms.

 

[spats]

civilperson-

I'd love to see your bar grating diaphragm calculations.