When designing a multistory [0] building, there’s quite a few different options to choose for floor framing systems. Floor framing is more loosely coupled to the rest of the building than other structural elements - it’s often possible to swap out flooring systems while leaving the rest of the building unchanged. There’s some limitations - you can’t use a wood framing system in type I or type II construction for instance. And some systems have more natural synergies than others - if the rest of your building is cast concrete, it probably makes sense for your floor to be concrete too. But generally for a given building, there are at least a few different options for floor framing.
This is good but you're a little bit off on your span capacity for dimensional lumber because you're using a DL+LL combination that's more aggressive than what Code allows for most residential occupancies. 10 lbs per sq. ft DL and and 40 lbs LL governs houses and non-public areas of multifamily dwellings. Only consequence of this to your data sets is that dimensional lumber wins the cost race by a slightly higher margin. However, I've observed that large scale multifamily design tends to favor wood truss floor systems because of easier installation of mechanical components.
Great article, is there any way to get a excel copy of Span v Cost graph or at least actual raw data?
Cheers
This is good but you're a little bit off on your span capacity for dimensional lumber because you're using a DL+LL combination that's more aggressive than what Code allows for most residential occupancies. 10 lbs per sq. ft DL and and 40 lbs LL governs houses and non-public areas of multifamily dwellings. Only consequence of this to your data sets is that dimensional lumber wins the cost race by a slightly higher margin. However, I've observed that large scale multifamily design tends to favor wood truss floor systems because of easier installation of mechanical components.