Floor Joist Seen some I had never seen before.

[Musicinabottle]

Pretty darn major ordeal replacing a joist for sure, but I've replaced quite a few over the years. When I doubled the size of my house, I went with 2X10 joists on account of the fact that they are much cheaper and I prefer the conventional 2X over your garden variety BCI floor joist for a number of reasons, though I must admit that those BCIs are very easy to use and come in any length you can physically haul out to your jobsite. Longest I ever used was 70 footers. Actually very few buildings even use plywood for subfloor, wall or roof sheathing anymore in place of OSB (oriented strand board)

[matt21481]

This is slightly off topic, but I'm trying to learn here. In the picture shown earlier, #1 is what is used in my house. Is it any better/worse construction wise compared with 2,3, or 4? I definitely see the benefits to running electrical/low voltage lines, but other than that, is there a structural benefit to any of them?

Thanks!