Question about acclimation

[Chris Dennis]

I’m building a small project that is essentially a box. I’m going to build a frame from 2x4 lumber and then cover with Baltic Birch (B/BB grade). Do I need to let either acclimate to my home first? I was thinking the Baltic Birch ply would be fine, but not sure about the 2x4. None of the 2x4 is exposed to view

[Andrew Seemann]

The baltic is probably fine, unless it has been stored in an overly wet or dry environment.

The 2x4s could be an issue, depending on how "fresh" they are. Construction lumber is typically dried to 19%. That is fine for a house, but most places tend to have lumber equalize out at 8-12%, depending on season. If you just bought the 2x4s, they might still be a little too wet. If they have been sitting around for a month or so in the shop, they likely are OK, or at least OK enough.

Also, when using construction lumber, watch out for fast grown wood with wide growth rings, like more than around 3/16 or wider. This wood can be unstable after it dries and be full of tension. Also avoid any lumber with pith in it or that has been cut near it. This tends to cup and uncup like a hinge at the pith line as the moisture changes. It is a geometry thing from the curve in the rings and the lumber changing size with moisture content changes.

[roger wiegand]

The price of KD poplar isn't much, if at all, more than the current cost of construction 2x4's (which was astronomical when last I looked) You'll save yourself a lot of headaches by going that route. It will be a much better match to your BB plywood and you won't be tearing your hair out as the 2x4's twist and bend once they're out of the pile.

[Chris Dennis]

The price of KD poplar isn't much, if at all, more than the current cost of construction 2x4's (which was astronomical when last I looked) You'll save yourself a lot of headaches by going that route. It will be a much better match to your BB plywood and you won't be tearing your hair out as the 2x4's twist and bend once they're out of the pile.

So would the kiln dried from box store work? I’m short on time as this is a surprise project while wife is out of town, but I don’t want to build then have it all shift and crack. Would 1 week in my house be enough time to dry to my homes moisture levels? Really no clue on how long that takes.

thanks!

[Andrew Seemann]

HD, Lowes, Menards, etc. poplar should work fine. If you can let it sit a few days it wouldn't hurt. Actually, if the boards are not wrapped and exposed to the air in the store, they likely should be good right away, assuming they have been at the store for a while.

[Bill Dufour]

Location and climate?

I have never seen poplar as framing wood just doug fir, redwood and unknown fir/pine/larch.
Bil lD

[Jim Matthews]

Kiln dried Poplar is excellent for frames. If the boards aren't thick enough, "sister" thinner ones together.

Choose like any lumber: sight down the length and choose the straighter, avoid knots or checks.

[roger wiegand]

Poplar from the big box stores is fine (it's in the trim aisle), but will be a lot more expensive than buying it from a hardwood lumber supplier. (And even more if you buy it from Woodcraft or Rockler.) As an example, at my local place 8/4 poplar is currently $3.05 /bdft, 4/4 #1 common is $1.70/bdft.