Silly carpenters almost NEVER put those holes anywhere close to lining up. Rare if they even think of it. Most can be drilled*, per manufacturers +/or engineers instructions. Always check with GC, and engineer if they can or can not be drilled, and for what size holes.
*Add a set of bits into the bid for the job, the glue in them trash bits like no one biz... 2 sets for a large job.
Here's a horror story about these. On a job 6-7 years ago, (When these were kinda new) the GC had a meeting about them, and said under no curcumstances should the ones on that job be drilled in any way. Everything in the cieling had to enter from the sides. (We ran a gutter down both sides and that was it for us, a pipe down each wall and a whip for each set of lights between the joists.) The building was open spanned from property line to property line, short dimention was 50', with several tons of AC equipment on the roof. The cieling had several sections with these engineered beams, and glue lams stacked next to eachother.
While I'm up in the lift at the gutters, I notice the Sprinkler guy drilling the mess right in the middle, so I yell over to him that he wasn't supposed to drill them, and we argue from two different lifts. "Just following the plans..." None of my biz, etc. The GC is no where to be found all morning. My boss shows up, and I tell him. So my boss calls him, and the GC is back in a flash. He then throws everyone off the job site, and he's hopping mad, throwing stuff. We don't go back for 3 weeks or so. When we do go back, there is a giant steel beam down the center of the building. And a new sprinkler sub... Apparently these all started to split at the 4+" holes that were drilled, but that probhably had more to do with the glue lams.
