Building out of Construction Lumber

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I am planning on building a dining room table bench, using plans i found online.  It will be mostly 4x4s for the base structure and a 2x6 and 2x10s for the seat part.

I purchased the lumber from a Home Depot when I was in the big city 2 weeks ago.  The plans call for a large pocket hole glue and screw construction.  Should I let the lumber age before building or not?

[R Clark]

Speaking from experience...I once built a harvest table with BORG framing lumber.

I built the table top from 2X8 framing lumber.  I didn't wait between purchase and construction.  The boards were glued up by jointing the edges and using Titebond.

It turned into a ski-slope hot mess within two weeks.  I ended up trashing the top and rebuilding the top with 3/4" ply and adding edges for a finished appearance.  This was in my early woodworking days, and I can say I learned from that experience.

So...to answer your question...yes, I think you need to wait and make sure it's as dry as possible before working the stock.

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Any suggestions on how to dry this wood?
How long to wait or how to test it's dryness?
I have a moisture reader I bought to survey boats but not sure how to use it for wood.
Would rough cutting the pieces into smaller sections but bigger than the sizes needed for this project help dry out the wood?

[adamcherubini]

1) Any suggestions on how to dry this wood?
2) How long to wait or how to test it's dryness?
I have a moisture reader I bought to survey boats but not sure how to use it for wood.
3) Would rough cutting the pieces into smaller sections but bigger than the sizes needed for this project help dry out the wood?

My Nicholson workbench is doug fir from Home Depot. 4x4 legs and 2x12's for the top. Its very nice, quite old now and uncracked. You can build good stuff out of construction lumber.

1) Stack and sticker it correctly to permit airflow. A ceiling fan or floor fan can help or can lead to cracks. The key is to immediately seal the exposed end grain. A couple coats of shellac will work as will a good rubbing with an old candle. Goal is to reduce moisture loss or gain at the exposed end grain to try to get the entire board to have the same moisture content. Super accurate width measurements are as accurate as a moisture meter for predicting cracking caused by rapid drying.
2) Depending on your joinery, you can wait or build immediately. If you don't have STIFF cross grain joints (I'd categorize screws as stiff) you need not worry, but I would continue to maintain end grain sealing for as long as possible.
3) Rough cutting WOULD help because you would be exposing more end grain and shorter pieces will have less differential shrinkage (which leads to cracks).

Traditional carpentry and furniture designs cover end grain: Fascias cover rafter ends, bread board ends cover table ends, London pattern dovetails reduce exposed end grain, miters, moldings etc all reduce or eliminate exposed end grain.

So too, traditional joinery seeks to permit wood movement by reducing cross grain joinery through the joinery design or allowing cross grain joints to breathe (like x-grain sliding dovetails).

If we want to build well, we just need to try to deal with our imperfect building material. Once we realize God made trees to produce oxygen and not coffee tables, I think we can build successfully out of any solid wood material. So construction lumber is as valid and viable as any other wood....if you know the tricks to building well with wood.

Adam

[Admiral]

Construction lumber is pretty wet, generally 18-20% (framing does not require much less than that) whilst furniture grade stock is half that, so yes. When I buy 2x stock, I keep it "in stock" in my shop for at least 3 months to dry and acclimate, so I tend to buy when I don't need it so when I do its sufficiently dry. So let it sit for a while before you joint and plane it square as there will be some bow and twist. Stack and sticker with weights.

[R Clark]

Harbor Freight has an inexpensive moisture meter for wood; it's what I use and I've had guys with more expensive units tell me the HF unit is just as good.

Yes, it will dry faster if you cut it to thinner pieces.  Make sure you don't cut it too much as it will shrink some as it dries.

Admiral's suggestion of a few months seems reasonable.

I just don't use BORG lumber for that purpose any more.

[Ohio Mike]

 Should I let the lumber age before building or not?

Four years ago I built a pair of trestle-style benches from big-box southern yellow pine construction lumber.

I brought the 2x lumber into my basement shop and stacked it up off the floor with stickers between the boards to allow air circulation.  I painted the end grain of each board to seal it.  My moisture meter said it was between 16% and 20%.  I checked it weekly until the readings stopped going down.  For me, in the winter time, with an indoor relative humidity of 45%, it took 5 weeks.  If it had been summer when my RH averages 55%, it would have taken a bit longer.

The boards twisted a little and I got some checking but I got rid of that in the rough milling process.  I let the rough-milled pieces sit another week before final milling just for good measure.

Those benches went into the mudroom of my daughter's house where the kids have "distressed" the finish.  Otherwise, they have held up well.


Mike

[Gary G™]

You could buy their kiln dried framing stock

[FS7]

You could buy their kiln dried framing stock

I think most of the untreated studs are kiln-dried. I have used them as supports in a lot of projects that ultimately ended up concealed but never had a problem with moisture. No splits, no warps,  nothing like that. They don't seem to do it in the shop either. For example, I have done a 75 gallon aquarium stand and the "framing" was construction 2x4s with a nicer outer shell. It might be the 900# of stuff keeping it stable but it does hold together very well. 

Treated lumber is a whole different story. That stuff is often physically wet and very heavy.

[Eurekan]

Agree you should measure your moisture content first. I've found construction lumber from anywhere varies widely from piece to piece. So, try to get it down where it stabilizes. Now, here's what I've done when I need to get the moisture level down quickly. 

1) Carefully stack it to prevent warping.
2) Build some sort of hoop enclosure. Nothing fancy needed.
3) Cover with a tarp
4) Stick a dehumidifier at one end and blow the dry air through. Or, put the dehumidifier inside and close it up. The heat helps.
5) Check often.

Works for me.