Welding to Steel Deck 2

[FootNMouth]

Is there any concern with welding a steel angle to 18 GA deck via fillet weld (1/8")? My initial thought it no since the deck is only .0478" thick. I believe the weld will burn through compromising the strength of the deck.

 

[jayrod12]

you could tack it to the deck to facilitate erection but I would not be counting on it for the final connection.

 

[UcfSE]

Check and specify your weld per AISI. It's possible to weld 18GA, but not if you spec a 1/8" fillet. Typically when I weld CFS I specify a fillet weld matching the steel thickness.

 

[KootK]

It's delicate work and, in my jurisdiction, would require a welder ticketed to weld deck. In the overhead position, I'd put your odds of getting a quality weld that doesn't burn through the deck someplace pretty close to zero. If you've got concrete over your deck, I'd recommend working out something with post installed anchors instead.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[jike]

Based on the detail shown, the angle could fall in the flute (depending on the deck layout and brace location) which could make welding more difficult unless an angle is used that has a large horizontal leg. Another alternate might be to puddle weld a flat plate to the underside of the deck first.

If there is concrete to be placed in the deck then a flat plate with headed studs could be tacked to the underside of the deck.

Another question.....can the deck resist the vertical component of the brace?

 

[jike]

If the detail also applies to the situation when the deck is turned at 90 degrees (flutes perpendicular to brace), does the deck have the ability to resist the horizontal and the vertical components of the brace?

 

[UcfSE]

In this detail, I agree with using post-installed anchors. Typically here I use expansion bolts.

 

[FootNMouth]

This is a composite deck with 4½" of NWC on 3" deck. The typical detail that we call out shows expansion anchors, the contractor was asking for a substitution which I wanted to have a good answer for him besides just saying no. The composite deck was designed for a 7 K point load (forlift traffic) with the steel deck ignored as positive moment reinforcement, so I am not concerned with the vertical component of the brace.

Thank you all for your responses.

 

[spats]

Agree with KootK. I'd use post installed mechanical anchors. Almost every anchor manufacturer have products intended for this very purpose. Examples are Hilti Kwik Bolt 3 and Red Head Trubolt, cut sheets attached.

 

[darthsoilsguy2]

this is not an AWS prequalified weld. You can't just put a note on the plan asking the A/E to confirm if it is acceptable. The Contractor has to prove welds are acceptable by submitting the WPS and PQR's to back it up for any welds that aren't prequalified. they also need WPQR's for the welder in the field. The A/E can review those documents, but the contractor is essentially asking the A/E to go into their backyard and weld it up, go through the code required testing, and get back to them on it... boo hiss.