Yes, I know it might not be practical to do this without errors and there’s reasons like running utilities through and quality control with inexperienced workers, but technically speaking, could you make stronger structures with less materials using stronger structural shapes? Maybe it’s just more pleasing to our eyes everything being straight and square and such, but what about utility canopies and tents where you want to have your structural members as light and portable as possible? Why do we not have tetrahedron shaped tents that have 3 small, collapsible, yet rigid poles and a firing they go in at the top instead of having long flexible ones?
In: Engineering
In addition to what everyone else said about sheathing/plywood/subfloors already providing the membrane action you’re looking for, it also means you need to either use deeper timbers, or you need to have a gradient of depths.
Imagine a square, 4mx4m. Assuming 600cts, you can use 6 joists, of whatever depth you need. It’s an easy calculation, since theyre all the same span, so one size fits all. Now try doing it diagonally. Instead of the max span being 4m, it’s now 5.7m. So span is up 50%, so our timbers need to be deeper to account for that. But what about the rest of the joists? Do we use the same depth of timber throughout, and spend that much more money on material, or do we make the tradie hate us, and specify a gradient of timbers depending on span.
Both of these solutions will result in a structure that’s more expensive, time consuming, and results in a deeper ceiling-floor cavity than your traditional joists + floor sheathing will.
And if for whatever reason you don’t want to use floor sheathing, strap bracing is both cheap and very easy to install
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