It isn’t metric. It’s just the only way to divide eight feet into five even parts.

It was meant to simplify, but it failed. Which is why it didn’t really stick.

It’s less than ideal. Hahaha.

You’d be hard pressed to find a brand new house built last year that’s actually square.

Most people would be shocked at just how rough the rough framing gets.

As a GC that likes to do the framing personally, I try to keep it as square as humanly possible… it isn’t fine woodworking. But I think it should be real close. 89° - 91° is typically not going to give you too much sass at finish time.

If nothing else, it keeps my subs from bitching too much.

On a similar note… I’m constantly surprised by how few framing crews I see that don’t use an eight foot level and a power plane to dial in the final framing. Some of these novice and journeymen guys don’t even know what I’m talking about when I bring it up.

It’s sad how we went from an industry largely made up of craftsmen to a bunch of meth heads pretending to be installers. Most guys will talk a big game about being a craftsman, but their idea of level and plumb has you searching for their meth pipe.

There are still a bunch of really solid guys out here getting the good work done. But it’s so hard to find them in the sea of shitbags.

And, in my experience, shitbags do shitty work. And it shows when you see just how far shit is off square, and considered “good work” these days. Scary, if you ask me.

In my neck of the woods, we see a lot of 19.2 OC in homes from that era. But, depending on your region/state, there may have also just been no enforced building codes at the time… meaning it very well could be totally random.

I’ve seen “headers” over main entry doors made out of weird shaped scraps of beadboard of all stupid nonsense.

A lot of times they just used whatever bullshit they had within reach. Especially in depression era buildings.

Eh… not always… not even usually, in my area. At least for interior walls.

Typically only walls perpendicular to the joists are load bearing (though there are rare exceptions).

Load bearing walls should all have proper point load (translating the actual load all the way down to the foundation in a direct path).

Though not always required depending on the region, double top plates are almost always used for load bearing walls, and not for partition (non loading bearing) walls. This is especially noteworthy if you are in a situation like I am right now with 19.2 OC main floor joists, 16 OC main floor studs, and 24 OC joists and rafters in the attic/roof. The double plate gives you a bit of latitude to work with for adequate point load.

For simplicity and consistency’s sake, I frame every wall at 16 OC in a typical stick built home. And that’s typically the case for most other builders in my area.

But, it’s also worth noting that some areas are fully ok with 24 OC 2x4 walls throughout. I definitely don’t recommend it. But you can get away with it in some places without a fuss.

Then, of course you get into engineered lumber, trusses, etc., and shit gets exciting. Suddenly, you have no interior load bearing walls, exterior load bearing walls are mostly header to accommodate an insulting number of floor to ceiling windows… all sorts of tomfoolery and poppycock.

But, anyway… when in doubt consult a structural engineer… don’t be that asshole that has to dig someone’s dead dog out of the rubble of the house you just destroyed by removing something you shouldn’t have. Engineers are often pompous douche bags (at least in my area), but they’ve saved my bacon a few times when things weren’t so cut and dry because of prior shoddy work that disguised major structural issues.

UBC was indeed initiated in 1927, but was only really used in the western United States. It was based in California, if memory serves.

The first national level building code was formed by BOCA (Building Office and Code Administration). The compiled code was first released in 1950, a full 35 years after the inception of the organization.

There are numerous state and regional codes that predate all of the aforementioned, of course.

But the first cohesive compilation of truly national code requirements was indeed in 1950.

Oops. Fat fingered it. 2000 for IBC is correct. Solid catch.

There really wasn’t any sort of cohesive code requirement of any sort until 1950. What we (at least in the US) refer to as the International Building Code wasn’t even established until 2000.

It’s been pretty much a piecemeal endeavor since Ye Olden Time.

~EDIT~ Fat finger number correction.

I’m currently renovating a house with 19.2 OC main floor joists, 16 OC main floor studs, 24 OC attic joists and roof rafters.

The attic joists also simply meet end to end in the center over a non-load-bearing 2x4 wall with a single top plate, and zero headers in the doorway openings in said wall.

Point load, and a great many other pretty essential things, basically don’t exist.

Shockingly, it’s one of the straightest, most level and plumb homes I’ve ever worked on… which likely has a lot to do with the fact that it’s all rough cut old growth Douglas Fir. Beautiful lumber, and still really straight.

But yeah… it’s a 1920s house built by the original occupant. The client is that guy’s granddaughter.

Very carefully pull off a piece of the baseboard. You can cut a 1/4” - 1/2” channel where the trim will cover it.

Once you find them, replace the baseboard using a little bit of Liquid Nails.

Just be careful if the top has been sealed up with caulking/paint. Use a sharp razor knife to very carefully slice that along the top edge.