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.
I think this is an excellent time to point out that curl quotes (“ ”) are what are typographically used for quotations and apostrophes and hash marks (" ') are what are used for feet and inches. So it would look something like:
“ 2"× 4' ”
(Spacing is still a bit ugly, I’d kern me some quote marks)
I know. I have nothing against the format in general, as it's plain text and will always be readable. I actually prefer it to Excel sheets, although a proper database is the nicest. It's just annoying that someone chose comma, a super commonly used punctuation mark, as default field separator for csv.
It's actually purposely milled to be under the nominal dimension because it's designed to be 2"x4" once the plywood or sheathing is applied. It's makes it easier to get walls that are the actual desired thickness.
Come to think of it I think we were modeling it as 3/4 on each side, because I seem to remember the 3.5” 2x4 stud becoming a full integer thickness with drywall on both sides
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.
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.
Yeah, once I get my garage sorted out (and buy a jointer or make a Jig for my planer) I'm going to start getting rough cut lumber and finish it myself.
I tried the sled with shims on my thickness planer. It worked, but it was certainly a pain in the ass and unwieldy due to weight and length.
Picked up a 6" bench top jointer. Not great at long boards due to length of the feeds. Picked up some roller stands hoping that would be close enough, but I moved and the garage needs a lot of work before I can try them out.
If you can pick up a full floor sized jointer and have room for it, you'll save yourself several headaches if you plan on jointing a ton of rough cut lumber.
if you own a thickness planer, you don't immediately need a jointer. You can flatten a face with a sled and shims in the planer, and joint edges a frillion different ways. I have a jointer and sometimes I use my router table for edge jointing.
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!
Construction lumber, especially pressure treated lumber, is sold so wet I don't think it really matters. I've actually never tried to calculate wood movement for construction lumber because who the fuck cares? But for furniture lumber which is dried to between 6 and 14% moisture, there is a formula:
width of the board in inches x percentage of moisture change * expansion coefficient for a particular species.
Yellow pine (extremely common construction lumber) has an expansion coefficient of .00263. A 2x4 (actual dimension 1.5" by 3.5") that undergoes a 4% moisture content change will grow/shrink 3.54.00263 = 0.03682 inches, or just over 1/32". That's in width; it'll vary by less than half that in thickness. Wood basically doesn't move along the grain; the board won't get appreciably longer or shorter.
Maybe they mill, store, and sell under the same moisture conditions?
Also, how big is the difference in size and moisture for the same piece of wood? I would expect that moisture is usually not higher than 90% and not lower than 10% or something like that, but don't know how it really is
Once it leaves the mill they go to various stores and regions with different conditions. Some places store them inside, others outside.
Once I buy it at the store and take it the site, it’s now different from the store. You should acclimate all lumber for 48 hours before using it as well, this is so the wood doesn’t swell or shrink more after installing it.
A 2x10 can be anywhere from 9-1/2 to almost 8-1/2 depending on final site conditions.
I think if I was you I'd go have a talk with your sawyer, talk about "man if I wanted my wood this wet I wouldn't have broken up with Meagan. Is your kiln in working order?"
You are just off on the amount that the wood can shrink from being rough sawn at 2” to final delivery. If one board came from a mill on a humid area, it would shrink less before milling meaning it will shrink more onsite, if the board comes from an arid region, it’s already shrunk lots before being milled. So won’t continue to shrink more.
This is the reason why you can’t predict the milled measurements and they use nominal sizes…. Not to mention the group is SPF, so it can be multiple species that shrink differently.
The difference between just basic book knowledge and actually using the material for a living mate.
Also, the hell is a sawyer? Wood comes from mills.
Okay, are we talking about "boards sold as 2x10s might vary in width from board to board?" Because I took you to mean that a given dried and milled 2x10 might move up to an inch, which it had better fucking not. Because yeah, the likes of Georgia Pacific are going to be a bit sloppy with the final dimensions of 2x10s, because it rarely matters that much for what that board is going to be used for.
I'm a woodworker, I buy rough sawn lumber dried over a period of months, I shop dry it for a couple weeks then mill it myself. I can predict with a fair degree of accuracy how much it will move.
A sawyer is an occupational term for a person who operates a sawmill. My sawyer's name is Bill.
Absolutely sure. It's not really a factor in construction because of how the structure is engineered, but woodworkers have to constantly think about it.
Wood expands and contracts across the grain, but not so much along it. If you take a board that has been in a dry environment, put it in a humid environment, and allow it to acclimate, it will increase in width and thickness but not in length. At the microscopic level, wood is kind of like a bunch of ropes glued together with sponge, as it soaks up water the sponge wants to expand but the ropes don't let it expand along their length.
Us woodworkers have to think about that when building things like doors, which might fit fine in the winter and then stick in the summer. It's why we build frame and panel doors like this:
The large panel in the middle can expand and contract so much that it might be a problem, so we literally put it in a box. The outer dimensions of the frame are made mostly of the length of boards so it won't expand and contract much, and the panel rests in a groove in the frame, not nailed or glued in place so that it can safely expand and contract as it wants to.
Attaching wide boards end-to-face can even present a situation where the boards want to move in different directions and they'll eventually break each other.
You can even calculate the amount of wood movement given the species, of the wood, the dimension of the board and the amount of moisture change, you can read about it here.
True, but the amount they shrink and grow across the grain tends to be proportional. A 2x4 is very rarely measurably different from 1.5"x3.5", but a 2x10 (like you've shown) is 1.5"x9 1/4" but is often anywhere between 9 1/8" to 9 3/8"
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.
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.
I agree with this. Use whatever system you need or want internally, but there's no reason to force whatever archaic or industry system onto a consumer. Logcutters also use a 1"=1/4 system and that is how they sell wood. A piece of wood that is 2" thick is sold as 8/4. Not 2". I get that they have their system but it seems dickish to force the consumer to use that system. There could be a good argument for it, but I've not heard one beyond "what, can't you do math?"
It’s like a 1/4lb paddy being a different weight before and after cooking. They can’t tell you the final weight, since it’s always going to be different. Same with wood.
The woods final actual dimensions can vary, so they tell you its original size.
A 2x10 can be anywhere from 9-3/8thick down do 8-3/4 depending on how it dries.
I get that. But this is for kiln dried wood. And this particular issue I'm bitching about isn't about net loss. It's selling wood using an internally useful measuring system instead of how the consumer would actually think about it. It's adding needless complexity, in my mind, when there's enough factors to consider.
What? The final dimensions of kiln dried wood can still vary. If they say 1-1/2 and you grab one that’s 1-3/8 you get a post like this.
So you say the original size, no one needs to do any math (what complexity are you referring to here?) since the final dimensions will always be different once acclimated at the site they will be used.
The consumer (people who work with lumber) knows how the system works. You don’t, because you don’t work with lumber.
If the boards were precisely measured in mm and binned accordingly, it would help no one because all construction techniques developed for use with lumber account for dimensional inaccuracy.
Building and working with lumber is different than working with manufactured materials like plywood or whatever.
You can buy planed or unplaned wood. Called “rough” lumber which is the nominal size instead. Usually only for pressure treated lumber, but it’s available in regular too.
They don't, but every plan and instruction going back a looong time refers to things that way.
Essentially, where they make the wood calls it a 2x4. So the places that process the wood calls it a 2x4, and so on.
The kilning and planing process used to be much less regular, so if you used actual, you couldn't buy four 1.5x3.5s, you'd get a 1.6x3.4, a 1.3x3.9, and so on.
The only consistent way to refer to it was the original sawmill size, and people who built things knew you had to measure the actual size of each piece of wood, or just accept the slop.
We got better at planing and kilning, and eventually the actual size was standardized. We still had all those plans and bills of material referring to things by their nominal name, to say nothing of the actual builders and engineers who were both used to the nominal measurements and didn't think it was necessary to change. So stores kept selling things by the name people expected when they were looking for products.
Most stores now label in both nominal and actual to accommodate for people who don't know this, since buying lumber and building things isn't as regular occurrence for a lot of people as it once was.
The consumer doesn't need to know it. The lumber mill does, and the people responsible for warehousing and logistics, they use nominal sizes because saying "two by four" is easier than "one point five by three point 5."
The consumer doesn't need to know the dimensions at harvest. But the lumberjack and the sawyer do. They care about how much of the tree was needed to make a particular board, not how much board the customer ended up with.
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.
That wouldn't surprise me, but also the standard has been around for so long, changing the size of standard lumber is probably harder than changing the manufacturing process (which is likely automated and computer controlled anyway).
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.
This, my friend, is no mere “group” of ferrets. It is a horrific amalgam of a quantity greater than 300, bound together with simple twine in a structure of horrific dimension in a way that could only have been conceived by a mind twisted in reckless disregard to even a most basic understanding of the nature of our world.
every house I've lived in has had something fucked up in it. Even if you have one guy doing everything correct, you have 20 other contractors coming in that can't do basic addition and subtraction, let alone fractions.
I don't think you're implying this is exclusively an American issue or anything but that's just the nature of construction unless you're paying top dollar for accuracy when it matters.
I've been on a hundred or more construction sites and I'd confidently wager that most houses don't match the plans perfectly because of unforseen reasons...equipment changing due to lead times, electricians running their conduit in the wrong stud bays, etc. I've had to do a lot of creative problem solving and design modifications are inevitable. That's the only thing I really miss from my old career
I am in chemical and material handling stuff and it's the same. What amazes me is when the project manager can't allow slack where slack is perfectly fine and allows slack where it isn't.
One guy I will never forget had endless meltdowns about tiny tiny stuff in software and completely forgot that water pipes need heat tracing until the insulation was already installed. Whole project, multi tens of millions of dollars, died because of that. On the plus side before it died the password on the HMI was 8 characters long and required a number and a punctuation symbol.
I'm just saying it doesn't matter if one guy is really good because on projects that require multiple people a good team is all that matters. As far as uniqueness to the US vs everywhere, its probably worse here in the US but we have a lot of checks for extreme fuckups so we tend to just have a lot of low-mid tier fuckups. The big fuckups are when somebody lies on their expertise (like that university post tensioned beam bridge that fell in florida)
Even when you are paying for accuracy... I went to a home once for someone who paid for the builders to get everything perfect; the walls were crooked and warped like every wall I've ever seen.
What I find is culture drives them out. I am pushed a lot to take away all decision making ability from the techs and electricians. This command-and-control organization system. Anyone who can change employment does and I don't blame them.
Treat people like they are worthless and they leave. No surprises there.
At a societal level young people arent getting the benefits of their work. We're getting what is paid for. They're paying those old guys pensions+benefits but their own has been cut to the marrow. Consumers pay isn't going to them. And good fucking luck to any of them trying to start up against behemoths both local and national that can nip them in the bud before they become competitive.
My parents just had a house built last year and there is so much shit wrong. The biggest thing I found is one of the alcoves on the side of their fireplace is a full 1.5" wider in the front than the back. You don't have to measure to see it. How the fuck the guy who did the framing, or the guy who did the drywall, or anyone else walking past that fucking thing didn't notice I have no idea. They sold their nice old house for that pile of shit and it's not even better even if you ignore all the problems. It pisses me off so much because I told them this was going to happen.
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).
You use the chart. How does mm of a wire, including insulation, tell you ampacity? As I said it is easy to imagine a thick wire that can carry almost no current. You can't pull that crap with AWG system. It tells you the single most important fact, how much current a wire can carry. There is no incentive for wire manufacturers to cheat the system since a thicker insulation wire just means more cost for them.
Which ties in nicely with the other charts. Tell me how much power you need a motor to deliver and what I have to deal with and I can tell you exactly what wires to use, it's bending radius how thick it is etc. None of which I can do in the CE system.
Ironically outer insulation does impact conductor ampacity, because the rated continuous vs peak loads depend on the heat resistance rating of the insulation.
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 :(
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.
It's weird because it's the size of lumber BEFORE smoothing the edges. Manufacturers take this inch a mile and the 2x4 (as well as all other dimensional lumber) has gotten smaller and smaller.
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.