[leoedin]

The limiting factor in most structural uses of wood is stiffness not strength.

You could build your floor joists out of scaffolding boards, but they'd bend unacceptably.

Stiffness is basically a product of geometry rather than strength. Making your wood stronger doesn't help you if you need it to be stiffer.

[kragen]

As you can see from Figure 3a at the top of the third page of the paper, this densified wood is about ten times the stiffness of natural wood, in the sense of Young's modulus. Stiffness is basically the product of Young's modulus and geometry, not geometry alone.

[dotancohen]

Does it remain so stiff for decades, as would be needed in construction? Many wood treatments' effectiveness fades after time.

[flir]

My assumption is that it would. Steam-bent wood stays bent once it cools and the lignin sets. It's a lot like thermoforming plastic.

There's another advantage of putting wood through a heating-and-cooling cycle: you remove internal stresses that cause it to twist.

[kragen]

I'm curious about that too. See my comments at https://news.ycombinator.com/item?id=44027557 for more.

[dotancohen]

Thanks, I actually just read that and replied there as well. I didn't even notice it was from the same person.

You've been extremely informative and helpful, thank you.

[kragen]

Thank you! I am not a specialist in the area so I may be overlooking something important.

[silisili]

Oh man if that's true I hope it replaces dimensional lumber for floor joists. I'm not sure which psychopath invented span charts for home building, but it's extremely rare I'm in a non-slab house where the cabinets and such don't rattle from just a normal person walking across the floor!

I ended up putting beams in to half the span across my own house because it got so annoying(I want to say they are high grade SYP 2x10s @ 13 or 14')

[turtlebits]

I-joists + glue and screws are just fine if you want to avoid deflection.