See my other comment - they are closer than you think in some sense, but there are too many missing variables to say anyone is right or wrong.
The annual movement of wood depends (basically) on the local RH swing, thickness, absorption/diffusion rates, and swelling coefficients.
So giving any percents here without more data is just incomplete.
This is assuming bare wood too, with no coatings/etc.
A lot of the bare percents you see are making assumptions of various sorts. Usually they ignore the diffusion rates/etc and shoot for EMC at some parameters (the calculator you linked does) because doing it for real require more complex math. The calculator you linked is better than most for sure, but it is still a simplification of reality where it may be off by orders of magnitude depending on thickness.
It will be much closer to reality for thinner pieces than thicker ones.
The figures I gave are annual movement. Initial shrinkage is larger when drying from green wood. The numbers (from the calculator) match my empirical observations very closely.
By the way your relative humidity figures assume constant temperature. Wood cares about absolute humidity (mass of vapor per volume of air), and temperature is the dominant factor in absolute humidity. Rainy day at +1C (100% RH) is less absolute humidity than a sunny day at +30C.
This matters to me a lot because half of my woodworking projects are outdoors or not temperature controlled indoors.
"Initial shrinkage is larger when drying from green wood"
?
It's not - it's exactly the same as anything else. The wood doesn't know it's green.
The calculator you gave is shortcutting it, and has an entire article in how they shortcut it the same way as anyone else, based on the swelling coefficients/etc, but assuming thickness is small enough to not matter.
If your projects are outdoors, you will be affected by more than just humidity - UV will also have a significant effect on the properties of your projects :)
The moisture transport is also not as simple as you are making it out to be, and has a not insignificant effect.
See:
https://gupea.ub.gu.se/handle/2077/54179
https://www.mdpi.com/2076-3263/8/10/378
https://www.sciencedirect.com/science/article/abs/pii/S12962...
Yeah, the coefficients are the same but the initial moisture content in green wood is much higher than the wood will ever get to after seasoning, it won't suck that much moisture from the air (unless you're in a swamp or something). So the annual absolute change in millimeters is lower than from green to seasoned.
I have my woodworking projects in temperatures ranging from -25C to +100C (sauna) and extreme humidity changes from near zero to 100% RH. It is a form of art to make wooden things survive that, and I don't always succeed.
Ummm, most wood starts at a much higher moisture content (50%-200% noting that this is as a percentage of fully dried so it can easily be over 1) than it will ever have after drying (typically 5-15%).
Frankly, the idea that a piece of wood after initial drying was moving even an in/ft (eg "only" 8%) would be pretty shocking. Even good joinery won't deal with much more than a quarter of that ~2%.
You missed my point, which is that initial drying is absolutely 100% not different than any other time. Wood, especially outdoor projects like the person is making, will definitely see states where the moisture content is as high, if not higher, than when the wood was originally dried.
Also, most green hardwood starts at about 30%.
No reputable lumber supplier is kiln drying hardwood that is 200% moisture content. That's crazy town.
Even if they dried it super slowly, it would end up as mostly checked/warped garbage that they couldn't sell.
Beyond that, wood is moving a lot, sorry you don't believe it, but its still gonna do it.
Rather than say it's "pretty shocking", and dismiss it, care to present any studies that back up your assertion?
I sent plenty, both in here and other comments. I'm not aware of any sourced, actual scientific research that says anything other than what i did, since I was careful to use cited figures from actual research studies, and not random pages on the internet about "wood movement"
I think you are also assuming a lot about how it moves and what 8% radial swelling/shrinkage really means that isn't necessarily true.
Also your point about joinery doesn't seem to make a lot of sense. While it's true that most joinery can't handle lots of flex, if everything expanded or contracted uniformly, it wouldn't be a problem.
You seem to be assuming the opening will not expand the same as the thing going into the opening. It will. That is why you try not to mix conflicting grain directions in joints, and why you see so many joints that go out of their way to do that (IE 90 degree mated dovetail boards are not made by two conflicting grain directions, the pins and tails are made of the same grain direction that happens to mate at an angle)
https://cad.onshape.com/documents/3e489410fcf65e1f0f82663d/w...
I made two tabs for you, one with a 25% transform and one without.
Notice the opening gets larger when scaled. So would the mate. They would still fit fine. The same is true if you made a dovetailed box. It would just become a bigger/smaller box.
I didn't bother to scale it differently for tangential vs radial but it wouldn't matter as long as the same scaling factors apply equally to the mate, and the mate is made the same way. As is true of most woodworking joints, on purpose.
So the only issue is if (assuming 2% was the limit) the non-uniformness lead to >2% difference somewhere that mattered.
All of this is also why wood glue has such expansion/contraction characteristics. if wood was only changing 0.1%, it wouldn't matter.
So far i've seen a lot of doubt but nobody else actually seems to be bringing any real scientific rigor to that doubt, or saying some silly things.
Please feel more than free, i'd love to see papers with real measurements that suggest something else.
Sorry, it's not true that "initial drying is absolutely 100% not different than any other time".
https://extension.oregonstate.edu/catalog/pub/em-8600-wood-m...
Fiber saturation is a thing and it rarely exceeds 30% for usable lumber.
I'm mostly going on what I've read though I went outside to measure a 30" fir just now and it's 100% (REED Pinless). The 100 yr old apple trees were over 80%, but that's not peer reviewed (nor is it pay walled). Maybe people can cut down trees and toss them straight into an Alaskan for exactly this reason? Firewood sitting covered outside is <10%.
As for pretty shocking. Yes it would be, if the 36" door (flat sawn book matched) to my house didn't open, because it was an inch too big (it accommodates <1/4"/ft). It's about a hundred years old, and I'm pretty sure that's never happened.
Again - Nothing in any of this says anything about the equations being different for green wood.
I don't even know what you are arguing and why - it seems to change with every post.
So I give up - you still haven't actually shown me a study that says it's wrong, and now your argument is "my door would be too big".
This is a silly discussion.
Since you still haven't given me a single scientific study suggesting the movement doesn't actually occur, I guess i'll offer you this and then walk away:
Is your door surrounded by brick or something rigid? Or is it surrounded by wood and blocking, like most doors? What species is it? What are the radial/tangential shrinkage rates? Is it painted or otherwise sealed in a way that would affect rate of absorption, like most doors?
As an aside, did you know that basically no door company will warranty unpainted doors because of exactly the issue you say doesn't happen? Just about every single one will say something on the order of "this door must be painted or stained within x days or the warranty is void", where x is usually <7, and will unequivocally state that unpainted and unstained doors will warp. Because they do! Like potato chips, a lot of the time.
There are some made to be bare unpainted wood, but it's not common and it requires different construction techniques. Most of them are not solid wood either, they are 1/4" or 1/2" veneer pretending to be solid wood. Otherwise, doors left exposed to the elements often totally fall apart in years. All the time. I can show you one that fell apart due to movement in <5 years.
Beyond that -
Doors surrounded by brick or rigid things frequently become too large to open/close at various times.
My home was built in 1929, and the doors are painted, but the jamb is surrounded by limestone or brick on all sides. Not a facade. The jam is up against well-set brick or limestone. This is actually a super-bad construction technique, since in most cases, the brick/limestone is a facade to avoid this issue. I can send you videos if you want to see what happens.
In the winter, it is about 1/2-3/4 inch smaller than it is now overall. I've measured it. It does in fact, become unopenable in the summer. It actually is right now. I plane it until it can be opened again. It will show a very large gap in the winter.
This is on a painted door, so not even one that is totally exposed to the elements.
This is uncommon, again, because most doors are not surrounded by highly rigid materials. If they are, it's a facade instead of structural. Those doors that are structurally unable to move, will in fact, break apart. This is one of many reasons totally solid wood doors are uncommon (besides weight and cost)
Since you seem big on anecdote, and your door is your baseline, there's a door for you.
Most people with historic homes would laugh at what you are saying. Since you say your door is >100 years old, i'm sort of shocked at your view.
For example, my wife's interior office door, is wildly out of square and plumb. By about 2 inches. The concrete foundation and tile is exactly in the same place, and perfectly level and square. No tiles have broken or cracked, and they are original to the home. Only the things made of wood are no longer where they should be. The two exterior doors in her office on opposite sides were built identically ~100 years ago. They don't even close to line up any more, and are easily 1" off. Again, foundation is exactly where it should be. only the wood has moved.
But still, i'm out since we aren't actually having a useful discussion that involves more than vibes about doors.
I don't know what you're saying either, because not only is it completely at odds with the measured data presented in a lumber university textbook, but you seem to be unclear on how moisture is even measured.
Please reread the section about fsp and measured MC, because it explains clearly why wood does not expand beyond it's fsp ~30%. Then look at the simplified MC% vs RH% table and read data for shrinkage vs MC for various wood types. No pay walled university papers required, it's not that complicated.
If your wife's door is 2" out of square you probably have a house framing issue not door expansion due to indoor humidity.
I've sawn enough timber and built enough decks out of them that I know wood moves.
Yeah, the Midwest is cursed for this reason. Humid summers with incredibly high RH for being inland while temperatures push 100° F followed by bone-chillingly dry winters with temperatures falling to -20° F (and relatively little relative/absolute moisture). But all our homes are built of wood and the consequences are pretty drastic.
Are there designs that exploit this effect? I want a house with walls that intentionally become more permeable in the summer, less in the winter, haha.