Side Lap Fasteners for Composite Decking 4

[JAE]

The SDI/Vulcraft Diaphragm tables show sidelaps as welded for composite decking but don't show anything for using #10 screws for side laps.

Can you use screws for side lap fasteners for composite decking?

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[MotorCity]

I have used screws instead of welds, but I can't point to a documented reference. It really doesn't make much difference for a composite slab since any diaphragm action is taken through the slab and not the deck. In theory, you could have no sidelap fasteners and you would still have composite action.

 

[JAE]

Well, but in the SDI and Vulcraft diaphragm tables, the number (and resulting spacing) of sidelaps definitely alter the shear capacity of the diaphragm assembly.

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[Huevo]

Hilti has published information using their side lap screws.

 

[WillisV]

Look in sdi's diaphragm design manual (now in 4th ed).

 

[MacGruber22]

Hilti Profis DF allows #10 screws. Not sure where they got the approval.

One in the hand is worth two in the bush.

 

[JAE]

WillisV - we just ordered it, thanks.

I'll check out Profis (which we have and use) - Thanks MacGruber22!


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[MacGruber22]

No problem, JAE. It actually surprises me they do - not because of capacity issues, but because I'd think they would want users to stick with Hilti mechanical fasteners. It is a pleasant surprise given how other manufacturers' software can be stingy with conventional materials and connections.

One in the hand is worth two in the bush.

 

[WillisV]

@JAE - that is one of those references you will end up keeping close at hand.