Bar Joist sizing for OWSJ for Sprinkler Design
Bar Joist sizing for OWSJ for Sprinkler Design
(OP)
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.
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.






RE: Bar Joist sizing for OWSJ for Sprinkler Design
RE: Bar Joist sizing for OWSJ for Sprinkler Design
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?
RE: Bar Joist sizing for OWSJ for Sprinkler Design
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
RE: Bar Joist sizing for OWSJ for Sprinkler Design
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.
RE: Bar Joist sizing for OWSJ for Sprinkler Design