Out of pure curiosity does anyone know where "new growth fir" lumber is the typical building material? In the US most homes are built using Pine but that can't be true everywhere.
Fir is used in the US (most commonly in the pacific northwest), it's just typically used for outdoor construction because it doesn't warp as easily and holds up far better outdoors than pine. So you will frequently see it used as decking, fences, or siding (although wood siding is getting pretty uncommon).
Fir is also sometimes used for framing like pine is but pine is usually cheaper. The only advantage fir has over pine for framing is that it tends to be a bit stronger. But there are very few places where you need that extra material strength and can't just use slightly more reinforced pine construction to acheive the same result.
Framing material in the US is called SPF, which means spruce pine fir. Any of those species may be used and they have similar enough engineering characteristics that they are interchangeable. Occasionally a building will be designed to use a specific species (southern yellow pine etc). But mostly we engineer stick built structures for SPF framing.
I've been out of homebuilding for a while but we're I was we largely used SYP and our SPF was all pine. Perhaps that was just the region I was in though.
I was in the rough carpentry game 20+ yrs ago so it’s been a while for me also. For the most part I think if you buy SPF you’re getting some sort of pine species. But it wasn’t super uncommon for us to find a couple dozen fir studs in a bundle.
The "new growth" part is because the trees are harvested from farms as soon as they're big enough. This is as opposed to "old growth" where the trees are more mature and stronger.
The maturity of a tree does not affect wood density. Density is determined by the stand density the year the ring is added along with factors such as soil moisture, temp etc. the inner rings will have the same density, whether the tree is harvested after a few years or after 200 years provided the tree stayed healthy.
I'm always confused by these kinds of assessments people make with some unrealistic test. Lumber for building a house doesn't need to withstand bites from a human jaw!
Years ago, Tesla advertised solar shingles that could withstand a bowling ball being dropped on them. Why?! Hail is a thing, but bowling balls don't fall from the sky.
Extending this concept, let's say I want to sell you a new motorcycle I invented. I won't demonstrate how well it rides or how fast it accelerates, but I will show you how deep I can submerge it underwater before the gas tank crumples — 4000 ft! Let's see Harley beat that.
It’s kind of got some “jet fuel can’t melt steal beams” vibes to it. The beams didn’t melt. The fire was just intense enough that it caused the tempered hardening to fail. Without which, they could no longer sustain the load of the rest of the building above it.
Architectural materials are designed to deal with typical loads, plus a decent margin of error. Most people don’t have beavers in their walls, so bite force isn’t a typical load. Neither is a fully-laden jet airliner crashing into your skyscraper.
In my state of Victoria, in Australia, it’s required to use steel frames for construction of homes in bushfire-prone areas. Fire is a typical load that meeds to be engineered for. However, a single-story house (we build out instead of up when there’s the space) doesn't need hardened steel beams, and without 100 floors to support it won’t collapse in a fire.
I mean he’s a beaver, he might be a little biased towards wood bite quality. Obv gets his fix on stuff that gets “lost” at the construction site, and they’re just not buying the good shit anymore. I feel for the rodent
Generally things are engineered with a safety margin so that they are absolutely safe for regular use and minor manufacturing defects or unusual usage don't cause immediate failure. That ladder rated for 400lbs will hold more than 400lbs before it collapses. Sometimes much more. This is normal and sometimes manufacturers like to show off how far above spec they are.
That said, the human jaw is quite strong, and structural wood is not generally expected to withstand high perpendicular shearing forces. I also don't really believe Tesla solar roofs would hold up to bowling balls, despite that being essentially a very extreme piece of hail.
Oh, don't worry. The bowling ball "test" was made before they had a prototype
Remember that day when Elon had an event in a neighborhood, pointed to the house behind him, and said it had solar roof tiles? When he held up a piece of pretty glass roof and said it was a solar panel?
He lied. He stood up there with a piece of glass, and he straight up lied to our faces... He lied with fake tests, fake metrics, fake prototypes
As the old saying goes, any old idiot can make a house that doesn't fall over. It takes an engineer to make a house that just barely doesn't fall over.
It's like those TV shopping channels showing you how many bowling balls a vaccum can lift. That is of course critical for a piece of plastic and electronics that sucks up dust. It's so stupid I can't help but laugh.
A suction cup could lift a bowling ball but will do dick all about the crap on your floors. Lifting a bowling ball is about static pressure while lifting a bunch of small things is more about generating high airflow. Based on this, I wouldn't be surprised if a vacuum cleaner designed to be able to lift a bowling ball is worse than one that didn't try to do something like that and just focused on shit a vacuum is supposed to suck up.
Though maybe a vacuum that could lift a bowling ball would be better for sucking a dick. Did they advertise how well it handles fluids in addition to the blowing balls? Maybe it was a vacuum like a magic wand is a back massager.
