My understanding is that there's a ton of overtime in construction work. The projects are on a fixed schedule (a Gant chart made in MS Project), but unpredictable things happen all the time, so overtime is necessary to catch up.
Depends on what you're referring to with overtime. If it means 24/7 rotating shifts to compensate for the unpredictable, yes, that absolutely happens. So it's not so much "overtime", is "off-hour shifts".
Again, this started as an "skyscrapers sites" analogy. If you have a guy working in such construction for 20 hours straight, you're calling for a (very possibly fatal or catastrophic) accident, and there's absolutely no insurance company that'll cover for that, among other problems you'll be calling for.
