Steel Extended End Plate at Roof

[ATSE]

My question is about a prequalified steel moment frame connection per AISC 358-16 and 341-16.
Roof connection vs floor connection.
My main references are AISC 358-16 and AISC Design Guide 4 (2nd edition), which don't appear to address single story frames, but instead also show figures and calculations for a continuous column above the moment frame beam - maybe I'm missing it.
Structure use: Large outside mechanical equipment cover with full height siding one side (3 sides open, 1 side sunshade)
High seismic area (Northern California), but wind controls stiffness and strength demand.
For medium size equipment shelters (say 20'x30') we usually use cantilevered HSS columns for the lateral system. When there is a full height side panel or for very large and tall open frames, the HSS gets large and the foundations get large - hence looking for frame action to resist wind and seismic.

1. The top deck is also the roof deck. Suggestions on clever framing / decking to provide from decent roof deck attachment and waterproofing, assuming that the approx 3.5" vertical column stub at the column locations (due to the top bolt row) is a necessity?
2. Is there a code-approved / recognized method to get rid of the 3.5" tall vertical column stub above the top of moment frame beam I've seen PEMB frames with "flush to top" end plates (that otherwise look a bit slender, as to be expected from PEMB framing). Seems like a silly question with an obvious answer, but looking for experience and don't mind getting smacked.

 

[jittles]

My first thought would be why do you need the pre-qualified connection? Is there a requirement to use a Special Moment Frame system?

Since wind is controlling, I would think you could go with an Ordinary system and then pick a moment connection you like without being limited to the pre-qualified types. I would think that the flush end plate (design guide 16 iirc) type would work in an OMF.

Seismic loads would increase moving from SMF to OMF, but I can't imagine they would control in this case.

 

[KootK]

That's the trouble with those prequalified joints. Not much deviation allowed. It would seem like a waste of material but I suppose you could weld an HSS to the top of the thing (not messing with protected zones). I guess that one can't rotate the joint 90 degrees either without losing PQ. Here, it wouldn't really matter if your hinges were in your beams or your columns.

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.