What moisture content can you bring wood inside at?

[FS7]

I milled about 2000 board feet of red oak last year. Mostly quartersawn 5/4, some slabs. This was in early November, so close to 10 months ago.

The 5/4 stacks are roughly between 8% and 15%. The 8/4 slabs are still pretty wet (25-30% in the middle). I was advised to air dry as much as possible because of the tannic acid content of the wood.

If it still needs to be stickered at that MC, I will leave it. My understanding was that it won't get to interior equilibrium MC outside ever and will stay right around the 10% mark, more or less. If I can stack it like normal dry wood at this point, I would love to. But as this is my first time drying this much wood, I thought I would ask.

[ianab]

Under about 20% should be OK to bring inside and complete the drying. At that level fungus can't grow any more, so poor airflow and slow drying won't harm anything. Also "most" of the water (and acid) has left the wood, so you aren't releasing huge amount of that inside your shop. 

So the 8/4 needs a bit more time, the thinner stuff is probably as dry as it's going to get outside. 

Where I live 15% is basically "dry" (EMC is 12-14%, even inside). But more Inland US areas, or air conditioned spaces, need to be dried more to stay stable. 8% seems a sensible number for most areas.

[Gary G™]

…
If it still needs to be stickered at that MC, I will leave it…. If I can stack it like normal dry wood at this point, I would love to. But as this is my first time drying this much wood, I thought I would ask.

If you don’t sticker it at this MC, I would expect critters to get into the wood.

[ianab]

And if it's still at ~15%, it still needs to dry some more, but that needs to be inside (or a kiln). So sticker it to complete the drying. It's OK to flat stack once it's down to your target moisture level. Probably more like 8%.

[FS7]

What I'm seeing is that it needs to be stickered inside for final drying. Which is fine, I guess, I just need to make a fair amount of room to do it (or do it in batches). I don't think the garage will be enough, unless I do a homebrew sort of kiln to speed up the remaining few percent.

[jteneyck]

Like much of the country, you need wood in the range of 6 - 8% for it to be stable for cabinet and furniture work.  So your 12 - 14% air dried wood needs to come indoors, stickered, and be put in some location where the RH will be below 45% much of the time until it gets down to that moisture content, after which it can be dense stacked.  Preferably, some breeze goes through the wood stack to assist in the drying.  

I built a small dehumidification kiln in my shed to dry lumber in the winter when my solar kiln is useless.  I had a similar kiln in my basement shop prior to that.  They are very simple and easy to build, even as a temporary structure.  The one in my shed looks like this.  




It's just an insulated box, with a fan to recirculate air, a household dehumidifier, and a small heater (not shown, but I use a $50 oil filled radiator), and a low cost RH and temperature controller.  I found as I used the one in the shed that I didn't even need a dehumidifier.  The heater and fan was more than enough to extract the moisture and by regulating the amount of air I let into and out of the kiln through two small holes, I could control the moisture loss.  Very simple.  

This type of kiln is even capable of sterilizing wood, when needed.  I could easily take it up to 140F and hold it there for a day or two to kill any bugs. 

The kiln in the photo holds about 400 bf of lumber and costs about $50/month to run with an ambient temp. near freezing.  When I had a similar kiln in my shop the operating cost was about $20/month.  

John

[Stwood_]

Or sticker inside. Lay plastic down on timbers, stack and sticker. Leave plastic ends open. Sit a box fan on one end and enclose it to pull air through the covered stack.
A little heat in the stacked area wouldn't hurt especially during winter