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Comment by bcrosby95 | Hacker News Reader

> There's "we bought a sawmill!" ads here in the rural lands now for fresh sawn green pine and oak; which isn't "lumber" yet in any useful sense. I've seen porches being built that won't last the summer.

I'm curious why this is. Is it the drying stage, or something else?

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You can build out of green lumber. But, as wood dries it will twist, warp, and crack. If you happen to live somewhere humid building with green wood is an invitation for fungal rot. For both durability and square building it is better to dry the wood first.

I'm sure there's plenty of "almost dry" wood in California.

You can frame up houses, but code usually mandates no more than 15-19% moisture before you can close the walls up, for exactly that reason.

Yes. The wood will twist and bend as it dries.

- Which, for those curious, is the the whole idea behind greenwood carpentry.

https://en.m.wikipedia.org/wiki/Green_woodworking

Its a shame more of that craft isn't going around. Granted, I'm not sure how a greenwood porch would work.

Green white oak, especially, can do some cool stuff. I imagine you could do a porch with lap built and grain matched construction and get a "tensegrity" bonus as stuff dried; but ive never seen that trick done with anything more complicated or smaller than house siding.

Wouldn't work well at all for any construction that isn't using mortise and tenon or some other type of friction fit construction. Can be disastrous for traditional construction where pieces are butted up together and nailed.

https://en.wikipedia.org/wiki/Wood_drying

Wood for construction needs to reach an equilibrium moisture point with the outdoor air after its cut.

If its dried outside, it takes months to years to dry, depending on the humidity level and temperature.

The wood is dried because it makes it lighter, and the shrinkage and swelling has already played out during the drying process... instead of when its in place!

Yes, wood that is used to build something before it has been dried will warp and curl.

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