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.

  • ferret@sh.itjust.works
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    6 months ago

    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

    • cosmicrookie@lemmy.world
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      6 months ago

      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!

      • SchmidtGenetics@lemmy.world
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        6 months ago

        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.

        • Captain Aggravated@sh.itjust.works
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          6 months ago

          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.

        • lad@programming.dev
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          6 months ago

          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

          • SchmidtGenetics@lemmy.world
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            6 months ago

            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.

              • SchmidtGenetics@lemmy.world
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                6 months ago

                These were bought at the same time and are both 2x10 installed a couple days ago. You can even see the difference in the connection in the picture.

                Over 3/8 of an inch and they both still need to dry.

                • Captain Aggravated@sh.itjust.works
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                  6 months ago

                  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?”

                  • SchmidtGenetics@lemmy.world
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                    6 months ago

                    9-3/8 is spec, the hell you talking about?

                    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.

      • Auli@lemmy.ca
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        6 months ago

        Bullshit. Wood expands and contracts so ther is no way you can be precious down to the mm.

        • intensely_human@lemm.ee
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          6 months ago

          I’ve not really encountered this wood expanding and contracting thing. Are you sure?

          • Captain Aggravated@sh.itjust.works
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            6 months ago

            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.

            • usualsuspect191@lemmy.ca
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              6 months ago

              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"

      • AnUnusualRelic@lemmy.world
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        6 months ago

        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!

    • themeatbridge@lemmy.world
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      6 months ago

      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)

      https://www.reddit.com/media?url=https%3A%2F%2Fexternal-preview.redd.it%2F6Oy1DmXVFs0lyKxq9OmjaI-2gsPj8QO6joLlY1rB7m4.jpg%3Fauto%3Dwebp%26s%3D4fa73a2eaf8d96d4de26378be1ba9c404b210685

      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.

      • 0421008445828ceb46f496700a5fa6@kbin.social
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        6 months ago

        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)

        • Auli@lemmy.ca
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          6 months ago

          I it’s like calling a quarter pounder a quarter pounder. You are not getting a quarter bound of burger after cooking.

          • lad@programming.dev
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            6 months ago

            And here I am thinking that it was a burger for reeeeally hungry people. No delusion anymore, it seems

        • gdog05@lemmy.world
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          6 months ago

          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?”

          • intensely_human@lemm.ee
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            6 months ago

            but there’s no reason to force whatever archaic or industry system onto a consumer

            Sure there is. Look up the concept of a “standard” if you don’t understand the reasons.

            Standards only work when they don’t change

          • SchmidtGenetics@lemmy.world
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            6 months ago

            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.

            • gdog05@lemmy.world
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              6 months ago

              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.

              • bloodfart@lemmy.ml
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                6 months ago

                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.

              • SchmidtGenetics@lemmy.world
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                6 months ago

                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.

        • SchmidtGenetics@lemmy.world
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          6 months ago

          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.

        • ricecake@sh.itjust.works
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          6 months ago

          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.

        • themeatbridge@lemmy.world
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          6 months ago

          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.”

        • Captain Aggravated@sh.itjust.works
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          6 months ago

          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.

        • strawberry@kbin.run
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          6 months ago

          its just easier to call it a two by four “yeah I gotta go out and get some 1 and a half by three and a halfs”

      • WalrusDragonOnABike [they/them]@lemmy.today
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        6 months ago

        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.

        • themeatbridge@lemmy.world
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          6 months ago

          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).

    • RememberTheApollo_@lemmy.world
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      6 months ago

      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.

          • ferret@sh.itjust.works
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            6 months ago

            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.