Attachment of roof deck

[Lutfi]

I have a situation that is as follows:

There is a steel tube that is connected to top of concrete wall (tilt-up panels). I have steel tubes that are and perpendicular to the continuous tubes that are on top of the wall. As you can imagine, I have 1.5-steel deck (18 ga) that spans on top of the rolled tubes. The continuous edge of the deck comes up to the radius/corner of the tube that is on top of the wall.

My question here is how do I fasten the deck to the tube so that I can achieve my diaphragm transfer to the wall. I have three options and wonder if anyone has input:

1.Fasten the deck through the corner with #12 screws that are being used to fix the deck to supporting steel. (Concern: full screw engagement may not take place due the corner on the tube).
2.Weld about 1.5 inches of the edge of the deck to the tube.
3.Use weld washer and puddle weld (get as much as we can) the deck to the corner and small vertical portion of the tube.

Any input and other brilliant ideas are welcome.


Regards,
Lutfi

 

[Ron]

Lutfi...a similar problem can exist at continuous angle embeds on top of masonry walls. Generally my solution is to make them weld an additional continuous angle along the tube or angle embed to provide full support, vertical and lateral, to the decking. Then you can fasten the deck to the angle, either mechanically or by welding.

The extra angle can be fastened to the tube by welding or mechanical fasteners.

Ron

 

[DaveAtkins]

If your diaphragm works with zero sidelaps, and you can transfer the diaphragm shear through all the connections at the perpendicular tubes, then you don't need to connect the deck directly to the tube on top of the tilt up panel.

DaveAtkins

 

[Lutfi]

Ron and Dave thanks for your input.

I elected to have them provide a continuous 1/8 bent plate on top of the deck that is screwed to the deck and to the tube steel. This provided means to transfer horizontal shear to vertical elements.

The detail was very mean and did not lend it self to adding a shelf angle and it was not accessible to weld.


Regards,
Lutfi

 

[geoffdale]

This may be a little late, but I know hilti has some mechanical fastenes that we have used for this type of situation.

 

[Lutfi]

Thanks for the positive replies.

I asked the contractor to utilize bent plate that would be screwed to the deck and to the steel tube.


Regards,
Lutfi