DanielOB said:
How about moisture in wood?
Do you check it prior to buy, or it does not matter. What would be the best moisture content?
Any reliable lumber yard should be able to tell you about the moisture content of the wood they sell, how it's dried (kiln or air), etc.
If you have your own moisture meter, you probably want to check with the employees if it's ok to use, as you often have to plane off a bit of the top of rough lumber with a block plane to get a good reading with a pinless meter, or you have to poke some holes if you've got a pin type meter.
"Best" moisture content is really what's acceptable to you, and depends on a lot of things. Maybe you could find some super cheap green wood somewhere that you plan to dry yourself. Relative humidity and moisture content are always changing, so you can expect different values at different times of the year. Of course, when building something, you'll have to take shrinkage and expansion due to moisture changes into consideration, especially if your furniture moves to different areas with different moisture values than where you live. For example, see Wood Handbook, Chapter 13: Drying and Control of Moisture Content (
http://www.fpl.fs.fed.us/products/publications/several_pubs.php?grouping_id=100&header_id=p), especially Figure 13-1 ("Recommended average moisture content for interior use of wood products in various areas of the United States"). They recommend 8% average moisture content for most of the US, but 6% in the dry southwest and 11% in the more humid south.
There's also an article for equilibrium moisture content for outdoor woods. It has tables for various locations by month, including a few cities in Canada. This might be helpful for any outdoor projects or if you're air drying your own lumber. See FPL Research Note 268 (
http://www.fpl.fs.fed.us/documnts/fplrn/fplrn268.pdf).
So really, the answer to the best moisture content is hard to answer. If you're buying kiln dried wood from a local reliable lumberyard, you probably don't have to worry. I've never checked moisture content in hardwoods from Home Depot or Lowe's, but I suspect it's ok (based on limited personal experience). If you buy softwood 2x construction type lumber from them, then it can be an issue. Some areas sell mostly green materials. Locally, we get kiln dried, but that's only down to 19% from the mill from what I've read. Going through the racks of 2x material, some of the newly delivered stuff feels really heavy and cool from moisture evaporating, almost damp. Some of the older stuff that's been on the rack a long time feels more like room temperature and is lighter, because it has had time to lose a lot of its water and come close to the equilibrium moisture content (and this is what I'll buy).
When in doubt, ask someone who works there.