DannyBee 1 day ago

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.

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kurthr 1 day ago

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.