re: screws to WF

[ake...@cfl.rr.com]

If attaching to WF beams, most erectors I have come across prefer puddle welds. I have been told anything over maybe 3/16" or 1/4" (the max thickness of most joist top chords I think) just becomes a big pain, screws break and it is difficult. I have had RFIs to switch and gladly went along with that. After a couple such requests we put puddle welds as an option right on the drawings.

LGSEA has several screw tables with shear, tension, pullout and pullover values, but likely if you use screws to attach to a WF beam it will be governed in uplift by pullover of the deck, not a failure of the screw. I would anticipate 18ga should give you some pretty good pullover values and may push the limit of the screw itself.

Not sure about ICC approvals...

Andrew Kester, PE
Florida

-------------------------

I don't know about ICC approval but United Steel Deck catalog discusses
screws along with welds. I would think screws would be acceptable if PAF's
are. The screws have a large head than many of PAF's. The PAF's sometimes
bounce rather than penetrate according to one craftsman (operator issue.)
Hilti and the Steel Stud Manufacturers have values for screws and welds for
light gage metal thicknesses to "heavy gage" steel.

Glenn C. Otto, P.E.
A Structural Engineer, P.C.
Virginia Beach, VA 23454
www.astructuralengineeronline.com

-----Original Message-----
From: Drew Morris [dmo...@bbfm.com]
Sent: Friday, November 20, 2009 6:09 PM
To: SEAINT
Subject: Steel roof deck attached using screws

Does anyone know of a steel roof deck manufacturer (1 1/2" 18 ga) that
has ICC approval for steel deck fastened to W beams using screws? I can
find reports of decks attached with spot welds and powder actuated
fasteners.

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[Harold Sprague]

Check out the data sheets.  http://www.njb-united.com/usd/ddds.htm
Of particular interest is the data sheets at the end for combined shear and uplift.  Numbers 46 thru 49.

Regards, Harold Sprague


 
> Date: Mon, 23 Nov 2009 21:00:38 +0000
> From: ake...@cfl.rr.com
> To: sea...@seaint.org
> Subject: re: screws to WF

---

Windows 7: I wanted simpler, now it's simpler. I'm a rock star.

[Scott, William N]

Note, the screws have 24 threads per inch,

 

Bill

---

From: Harold Sprague [mailto:sprag...@hotmail.com]
Sent: Monday, November 23, 2009 1:23 PM
To: sea...@seaint.org
Subject: RE: screws to WF