Bar Joist sizing for OWSJ for Sprinkler Design

[Flounder56]

I am working on a sprinkler design for several warehouse/commercial buildings with Open Web Steel Joists.
Trying to located my sprinklers as to prevent obstructions to the sprinklers due to the Joists. The sizes of the OWSJ have not been determined.

What are some typical sizes that are used? I pulled out my AISC Steel Construction Manual and sizes for the double angles can range from 2"x 2" to 8" by 8". I don't work in this field so any input would be appreciated.
I typically have only seen 2"x 2" double angles used. Are other sizes typically used, or reasons why I haven't seen the other sizes?

Also the joist depths are typically 30" to 36", would it be a safe assumption to assume that a typically joist depth would fall into this range?

Thanks.

 

[SteelPE]

Kind of a broad question. Chord sizes are going to vary by manufacturer, joist length and loading requirements. Joist depth is going to vary based upon joist length. loading and serviceability requirements. Your best bet for joist sizing is to contact the structural engineer to see if you can get some information out of him. In regards to the member sizing, withing the joists (panel point locations, chord size, web size) this information will not come unit the job is ready for fabrication.

 

[JedClampett]

If you want just typical sizes, you should talk to Vulcraft or a company that produces these.
But it's going to be almost impossible to pin these guys down. Different manufacturer's use different shapes, Some use round bars and some use angles. They might use different sections for the top and bottom chords. Maybe they got a deal on 1 1/2 inch angles, so they use those. By my observation, most of the members for the K joists tend toward smaller sections and for girder joists are larger. But the manufacturer is more interested in depth and load carrying capacity, not individual component sizes.
Why are you worried about this? Can't you route the pipes under the joists and point the sprinklers down?

 

[msquared48]

And these are open web joists. What is the problem?

Just give the sprinkler contractor a little latitude in the placement. A foot or so one way or the other should not matter that much, coverage considered.

Mike McCann
MMC Engineering

 

[BUGGAR]

My vote is that if you cannot complete your design and layout because of a lack of supporting information, then you have a legitimate cause for an RFI(Request For Information), and the Owner (or whoever) owes you this information.

If you need to get their attention, ask them if they designed the OWJ's for a Type ID 10t collateral load? Look very very grave when you ask this.

 

[Triangled]

for that span, assuming joists at 8' oc or so or less (ie not girders), i doubt you'll see any double angled chords larger than 3"x3"