I've just started working on this garage:
(http://design.medeek.com/images/slideshow/gambrel_stairwell_assembly_1024.jpg)
(http://design.medeek.com/images/MISC/BARN5030-A6D-2_ROOF_FRAMING.jpg)
My question at the moment is how to handle the ladder framing between the girder joists at the dormers. Usually I'm using dimensional lumber but this time around I've had to use an LVL bottom chord of 11 7/8". I don't think there is any dimensional lumber that is larger than a 2x12 to ladder frame the floor between the girders, so do I have to use LVL here as well? My thinking it is going to get expensive with all that LVL but then again that is the price you pay for a 30' clear span attic with trusses.
LVL also comes stock in 11-1/4" depth, I'd try that first. At 11-7/8" I'd probably rip (and plane if neccessary) 1x to furr the thickness of the dimensional. There should not need to be a splice plate in the LVL's. We did a whirlwind 2k mile road trip to marry off another nephew this past weekend, got to see a restored woody on the road, we also rode alongside a semi with a load of 4' wide lvl's. They are manufactured at that width and then ripped down, usually right behind the glue machine. Not sure what they were going to be used for but they were different lengths. I've never used deeper than a 24", these were quite impressive.