How long does wood take to dry (faster than I thought it would)

i would suggest to check with a wood humidity meter. equilibrium doesnt necesarily always mean the wood is dry, sometimes rather the environments capacity is reached. personally for my work i use timber with a humidity around 7-10% which is well enough dry. some of the timbers i harvest can take years to reach this low humidity if air drying. but then again the local timbers here in spain are all more dense than the common american hardwoods.

Forgive me if this has already been asked but does species make a difference or where it falls in hardness?

I have yet to use any "raw lumber" meaning something I didn't buy already perfectly cut from home depot. I do notice they (home depot) sell some rough cut pine that still has bark on the sides. But I don't have a jointer, or a decent table saw, so for what I'm doing I'll stick to the ready to go wood from home depot.

I’m impressed that they don’t have any checking

Soft woods, like red cedar reach equilibrium faster than a New York minute but still seem to dry inversely to thickness.

you said 6 months, but i heard 4 months

Did you seal the end grain or no? I think that would affect the drying rate if you theory about the shorter wood drying time holds.

Most firewood is cut in the spring and ready to burn in the fall. Long boards will take much longer to dry, for the reason you explain in your video at 2m30s.

You're only guaging weight, not moisture content %age with a meter??
Also you're storing it vertically, wood is generally stored horizontal to dry out evenly

I did that with a hemlock plank I had milled from a fresh log. Lost about 50% of weight over a month or so.

Wood dries EXACTLY one inch per year (with a suitable definition of dryness).

Maybe you could try two equal sized pieces and then wrap the end grain (both ends) off one of the pieces in plastic to see if the moisture is mostly escaping thru the end grain or not. That would be interesting I think :)

Very useful info

👍

Interesting video. But too fast drying is not good either. The wood will warp and or crack. For properly drying, the end grains should be sealed (to slow down the
process of drying) and the wood should be "stickered" to have air flow between all the different pieces.

Thank you, this is great. I would have liked to have seen the results of your moisture tester too.

Birch dries much faster than most other species - I have the same experience with birch from my own garden - not exactly the same species of birch as I live in Denmark but nonetheless...

This is very interesting! I've always wondered how fast wood needs to dry and like you thought it takes quite a long time. But, with this and at least for shorter pieces, it doesn't take very long at all. Now I'm curious just how long it would take longer peices to dry.

Had you sealed the ends of the wood prior to drying? This also doesn't take into account the porosity of the xylem/medullary between different species

Try a vacuum kiln. It’s like lightning in comparison. Green to dry in 3 days, not kidding.

Funny how the internet coincides with one's life. I just cut some somewhat wet birch to use for a knife handle and set the pieces in the basement to dry. I cut six inch long blocks about 2x4 size.

Let wet wood dry in the California summer sun and you could build a boat without forcing any curves.

So I can chop down a tree, cut it into chunks, cryogenically freeze myself for four months, and then wake up and have wood.

Good treatment of the subject.
The pine family or whatever you call it seems to dry (and also absorb moisture) fast.
Good sound board material.
I hope laminates will be discontinued, unless they're a cheap option for beginners.

I wonder if drying time would have changed if you sealed the ends, either with paint or a commercial end sealer like anchorseal?

Should've recorded humidity where the wood was stored too

The slower the cure the better the wood. A friend was given two slabs of old growth cherry. They were 4 inches thick ,8 ft long and 4ft wide. They were coated with lacquer all over, and had been drying in the rafters of a barn for 30 years. He made an incredible table from them.

Posted Jun 17 but the weight was recorded Jun 18....like WTF...

An interesting thing about this "common wisdom" is as in USA people would tell you 1year/inch, in Europe same "common wisdom" tells you 1year/cm. It seams pretty unrealistic to assume wood takes about 2.5x more time to dry. That should be sufficient to call all this common misconception instead of wisdom.

I have purchased two by eight pine boards to make book cabinet. Boards came just from forrest, so I lay them drying for over a month now. How more should I wait?

If I remember my studies of the one-dimensional diffusion equation, the time for a particle to diffuse a given distance in a porous media goes as distance squared, so I would expect the drying time to increase by a factor of four for a doubling of length. Of course, a log doesn’t dry strictly in only one dimension, and a board certainly doesn’t, so I suspect the rule of thumb is a better approximation for a board that is very long compared to its thickness where moisture is diffusing laterally very slowly in addition to diffusing lengthwise. Sounds like some additional experiments are in order!

It's a year per inch of thickness for lumber. What you have there is firewood and the rule of thumb for firewood is 6 months without a dimensional component since firewood is typically only around 16 inches long.

Length probably has more to do with drying time than thickness. Trees are set up to move moisture along their length. The fact that longer boards tend to be thicker boards is probably why the rule of thumb is for thickness rather than length.

So how long would it take if you applied wax or paint to the ends of the boards? I thought the goal was to slow the drying to an even rate so the wood doesn't warp as bad.

Wow that is one old version of excel :) is it ‘98?!

I always thought it was 1 year per inch if the ends were sealed with something like anchorseal to stop defects, forcing the majority of the water to exit the faces of the board.

Didn't notice if you did, but you should correct for monthly average RH XD

please do this again for all sizes and types of wood.

Your the most intelligent lumber jack ever !!!!!

Birch can hold and lose a lot of water quickly , however a denser wood would have different values. I've had birch be ready to burn in a few weeks at the height of summer before, while oak can barley be ready after 8 months.

I understand theres a conventional wisdom, but I think that has to do with whole logs reserved to be processed for lumber, meaning slow drying to reduce the amount of warping, and waste from end grain checking. I have some wonderful 18inch thick cherry logs set aside for that purpose, and they still have about 3/4 of their original weight after about 3 years.

Next: watching paint dry. Inquiring minds want to know! 🙂

With oak firewood split into pieces 4 to 6 inches in diameter and 24" long it seems like one hot summer will get them about 80% of as good as it's going to get. A whole year probably bumps it to 90% while 2 years is a good as it gets. Or at least as good as i can tell the difference just by burning it. That's in Missouri, outdoors sitting on concrete. With ash, it seems to dry by the time it's stacked lol.

The "year per inch of thickness" still holds true. He admits himself that his results may be because he used short pieces. In my experience air-drying lumber the top and bottom eight inches of the board dry out ten times faster than the rest. If his test pieces of the 1"-3" were more than three feet long then it would have taken at least three times as long to dry out IMHO. Additionally, once a piece of lumber is more than 3 inches thick the deepest portions may never actually dry out with some species. I have drilled into 4" thick oak that has been indoors for four years and it was still moist to the touch.

So, looking at the 50 year old floorboards in our house, those gaps between the boards were pretty much fully developed after just three months.

Good info, Thank you

Random thought popped in my head you’re video answered my question

Needs a LOGarithmic scale.

I noticed that you had placed your pieces vertically in the shed. I remember hearing that wood dries out quicker when placed vertically and that some woodsmen or pioneers leaned their boards against trees to expedite the drying so they could work with it or burn it faster. Cool video!

this is why science is important

That's encouraging info, I sliced some walnut into ~1in boards just a year ago. But I glued the ends to avoid splitting so I guess it's bound to dry slower 😂