I dont know why they have to lie about it. At $5/8ft board you’d think I paid for the full 1.5. Edit: I mixed up nominal with actual.
Shouldn’t the normal size be 2? Given, well, the name?
You’d think so, but no.
Short story is the ‘nominal’ size is the size before going into a planer to smooth the faces.
Yes, it makes little sense, like many things related to construction stuff.
Yeah sorry. The tree was originally 50ft tall so we call the pieces that. But you only get 3ft
Is like buying 1200lbs steaks because that’s what the cow weighs before it gets parted
This one of those things that sounds correct, but isn’t even remotely true. Like not at all, not even based on anything even.
Wall finishes varies in thickness wildly, and the milled wood also varies in final dimensions depending on moisture content.
Factually incorrect; the board is 2 inches by 4 inches (or whatever the marked dimension is) when rough sawn. After kiln drying and milling, it will be 1.5" thick and 3.5" wide. It still took 2 by 4 inches of the tree to make so that’s what you pay for.
The two-by-fours at your local home center are not 2 inches thick or 4 inches wide…not anymore at least. They spent several weeks at that size though. The sawmill cut them to that size to stack and kiln dry, and then when removed from the kiln they are then milled straight and square. Used to be they would sell the rough stock to carpenters who would do the milling themselves, but then they figured out that the railroads were charging them a fortune to ship a lot of wood that was going to be ground to sawdust anyway, so they started milling the boards before shipment. Same amount of construction lumber arrives at the construction site and it took less fuel for the locomotive to deliver it.
they are then milled straight and square
Lol. Trying to find lumber that’s straight and square is a pipe dream these days.
It was straight and square when it was milled. Problem is that the big box stores cut corners during the kiln drying phase, so the boards have a ton of moisture still in them. As that dries, the boards twist and cup.
Plus poor protection from the elements at each storage step, which means rapid temp changes, which also causes wood movement.
Go to a local lumber yard. They tend to do a better job at kiln drying. You’re still going to have warped boards, but far fewer in my experience.
Lumber is weird because it has been industry standard to lie about dimensions since before the US existed so it’s just kinda a thing they get to do
No its not Maybe in the US? At least here, it is and has to be, very precise especially when it comes to industry quality. It is precise down to the mm!
How does that work when wood varies due to moisture content? If they give precise mm measurements, only 20% of boards will meet those criteria.
All they are giving is the planned dimensions instead of nominal in mm form, it’s still not precise, it can’t be.
Bullshit. Wood expands and contracts so ther is no way you can be precious down to the mm.
That’s crazy, how can you make a profit if you give the customer the exact measurement? You have to saw a bit off and pad your earnings!
It’s not exactly a lie, just a standard. Nominal board sizes were based on the unfinished lumber size. Another 1/4 inch is taken off each side to get a smooth surface that makes it easier to work with.
Here’s an old image (reddit warning)
that shows the rough cuts of boards from a log. When they look at a log, they determine how many of each size they can get from it, and at that point, a 2x4 is 2 inches by 4 inches.
Why does the consumer need to know the dimensions at harvest when it’s been processed multiple times?
That’s like calling an 4oz can of evaporated milk a gallon because it came from a gallon of milk before processing (I have no clue on the ratio)
at that point, a 2x4 is 2 inches by 4 inches.
From my understanding, as tools have gotten more precise, the raw boards have gotten slightly smaller to reach the same standard size with less waste. So, 2x4 doesn’t even refer to modern unprocessed 2x4s, but rather a hypothetical unprocessed 2x4 at some point in the past.
Not entirely true. I lived in a house that was just over a century old. The framing was exactly what it said it was, a 2x4 was 2” by 4”. Same for all the structure. These were mill cut, but still pretty clean. It was WW2-ish and after that we started to get planed lumber that gave us 1.5x3.5. It wasn’t even until probably the early part of the 1900s that lumber started to become “dimensional”, as in the standard sizes we know of today.
As if american measurements have ever made sense. Look up how they measure screws or wires and despair.
Or shotgun shell sizes and loads.
“It all started in 1840 when the dram was a common unit of measurement…”
It’s a wonder they manage to build anything. They have pocket calculators dedicated to the building industry. It’s surreal.
The European wire gauge system makes no sense. There I said it. I don’t need to know the O.D. of the wire, I need to know the amp rating. The O.D. only becomes an issue for bending radius and there is a chart for that as well. Nothing is stopping some a**hole from making a wire almost completely out of plastic that has the O.D. of a typical 14AWG but can’t carry any serious amount of current under the European system. Under the AWG you always know what the current capacity is.
And while we are at it, you might as well standardize your wire sizes based on copper. You are never going to use anything except copper. So your units should reflect the material. I am building a chemical skid, that has nothing to do with the distance between the equator to the north pole.
Also when is the last time you were running wires that you needed a mm of precision? Meanwhile a fraction of an amp really does matter. So should not the thing that does matter be reflected in the product?
European wire gauge is not the outer diameter. It is the cross section of the conductor inside the wire in mm^2. It is the same system AWG uses (they are directly correlated) with the added benefit that the numbers make sense (10mm^2/AWG8 wire has 4x the cross section of 2.5mm^2/AWG14 wire, so a quarter of the resistance of the thicker wire and thus roughly double the current capacity).
The convention is 2" before milling. Milling takes off 1/4"on each side, so the result is 1.5".
Is this a joke? (I know it isn’t).
Why would I want to know the dimensions of the unfinished product? I’m not a construction worker, so honestly is there any reason?
They were when the name was made, but due to changes in the manufacturing process, they aren’t anymore. The name stuck, though.
https://www.popsci.com/two-by-four-lumber-measurements-explained/
So don’t fret. The next bundle of 2-by-4s you pick up in the hardware store are certain to be the exact same size: 1.5-by-3.5 inches.
So they can measure precisely, after all
It’s due to the milling to square it.
You can get rough cut 2x4 or 2x2 or anything that are actually that size but by the time you trim and square it you will end up at the measurements sold in big box stores
Edit: I mean the size they used to be in store, not OPs version :(
It was done for largely sensible reasons.
https://youtu.be/WaJFudED5FQ?si=7j005FmfJVr_JQL_
In short, a 2x4 was originally 2x4 inches, full stop, but it was found that this size wasn’t necessary for the strength being applied to them in construction. We were wasting lumber for no reason. They went through a few cycles of sizing down as the actual needed strength was understood better. The naming convention stuck, though.
Here is an alternative Piped link(s):
https://piped.video/WaJFudED5FQ?si=7j005FmfJVr_JQL
Piped is a privacy-respecting open-source alternative frontend to YouTube.
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Even if it was 2" from the lumber yard, it would shrink or expand quite a bit depending on the moisture content. Expecting natural products to be an exact size would be crazy, especially when talking about construction lumber.
Now this is a very extreme case, but it was probably milled to 1.5" soaking wet, and shrank a bunch after drying out on the rack. That’s also a big reason why they’re all warped.
