Ah, but I haven’t done engineering for years, and haven’t built a house since the eighties - not that I would ever have even looked at plywood beams or laminates! Built to last, not to cost.
From wiki:
“The advantage of I-joists is they are less likely to bow, crown, twist, cup, check or split as would a dimensional piece of lumber. I-joists' dimensional soundness and little or no shrinkage help eliminate squeaky floors. The disadvantage is very rapid structural failure when directly exposed to fire, reducing the time available for residents to escape and increasing the danger to firefighters.”
Gurt thick lumps of timber, properly seasoned so they don’t bow, crown, twist, cup, check, skeller or twist, are the way to go for me. Good for a couple of centuries.
