Building out of Construction Lumber
#21
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
I agree with using a moisture meter. I take mine with me to Home Depot so I can take the drier pieces in the stack. I’ve measured moisture levels in the “kiln dried” 2x lumber from 8% to 32% (I believe the max my meter reads), sometimes within the same stack. There can be huge variability.

I’ll generally only take pieces below about 13%-14%, depending on how desperate I am and whether my project can handle some twisting. I like to let them acclimate in my house for a few weeks before using them and check again with the moisture meter before use.

Tyler
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#22
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
Quote:The key is to immediately seal the exposed end grain

Important with hardwoods especially if drying from green. Not usually necessary with softwood. If you are going to get end checking it starts in the first stages of drying, and end coating after that is pretty much a waste of time. 

Everything else is correct.  You want air flow and some warmth to dry the wood out, basically like drying out laundry. So a flat base, approx 1" sticks to separate the layers in the stack, and some form of fan to move air though your stack. You can use a dehumidifier if you have one, that pulls moisture from the air (in the room or under the tarp), and lower humidity means faster drying. 

Construction grade wood is only dried to about 19%, which is enough to stop it rotting. It may be a bit less than that if it's dried more in the store, but it's very unlikely to be under 10% which is what you usually need for furniture. Hence the advice to stack it up and let it dry some more. 

Another trick to judge moisture content is to weigh a board. Note the weight, and put it back in the stack. Weigh it again after a few days, and it should weigh less if it's lost moisture. When it stops losing weight after a month or 2, then it's "dry". You don't know exactly how dry, but it's the correct level for the conditions it's been in, and isn't going to get any dryer where it's currently sitting.
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#23
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
I don't know what's available in your area, but down where I live the only 4X4s available at the home centers are pressure-treated.  There are two problems with those: 1. they are sold absolutely soaking wet, and 2. any regular steel fasteners used in them will quickly deteriorate.  So if you got treated 4X4s, then I recommend that you not use them--at all.  I would saw out and laminate 2X stock to the required thickness instead.

Time to dry is impossible to tell, really.  It depends on too many factors--the moisture level of each board, the relative humidity in your workspace (and in your home), the way you store the wood, etc.  It could all be ready to use right now (unlikely), or it could take another year to dry out.  The way a lot of this stuff is kiln-dried, it's case-hardened.  The outside of each board is bone-dry, but the inside is still wet.  It takes a while for that kind of board to come to equilibrium, and when it finally does, then you can see the shrinkage.  Often the middle of the board will be sunken a bit.

Mostly, though, the amount of moisture you can tolerate in the wood mostly depends on the project you're doing.  Some projects are designed to accommodate a lot of shrinkage, and others aren't.    If this is a relatively "rustic" bench that will be painted, I see no reason to wait.  Cut everything to length and start screwing it together.  Work quickly, and you'll minimize the inevitable warping as the wood dries.  (In other words, don't cut everything to length and then let the workpeices sit for a week.  That's asking for disaster.  Get the pieces joined up as you cut them, and you'll minimize warping.)  You might get some end-checking eventually, but as long as shrinkage in width isn't a big deal to you, then it doesn't matter. 

I'm guessing that these plans were drawn up with construction-grade 2X stock in mind, and if that's true, let's hope the designer had the foresight to plan for a considerable amount of shrinkage, too.
Steve S.
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#24
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
I have used yellow pine 2x lumber for various things. I understand the OP already has the lumber but in general one recommendation is to get 2x10 or 2x12 and cut your parts out of those. Cut out the pith as needed. Leaving in the pith almost guarantees things will crack. I also concur with the comment above to laminate 2x material rather than using 4x4. Frequently, the lumber I use has been sitting around for awhile so it is drier than newly purchased stuff.
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#25
  Re: RE: Building out of Construction Lumber by gjohn (I have used yellow p...)
(09-18-2020, 09:57 PM)gjohn Wrote: one recommendation is to get 2x10 or 2x12 and cut your parts out of those. Cut out the pith as needed. Leaving in the pith almost guarantees things will crack.

Agreed, a 2 x 12 has to come from a reasonable size log, and should be better quality wood. A 2x4 can be made from a ~6" log with a "chip and saw" mill. If the mill has to they will saw an 18" log into 2x4s, but they would prefer to make more valuable 2x12s from it, and produce the construction grade 2x4s from the smaller logs that wont make anything else. 

Wood close to the pith of pretty much any tree is going to be trouble. It can crack, or it can be "juvenile" wood that is weaker and shrinks in length enough to notice, leading to all sorts of warping.
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#26
  Re: RE: Building out of Construction Lumber by gjohn (I have used yellow p...)
(09-18-2020, 09:57 PM)gjohn Wrote: ....... get 2x10 or 2x12 and cut your parts out of those. Cut out the pith as needed. Leaving in the pith almost guarantees things will crack. 

ive found some nice stable qs stock in both of those.
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#27
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
FWIW my carpenter son put me on to the fact that precut studs are a higher quality then plain ol' 2x whatever. Didn't believe it at first but yep he's right. Look for the precuts and you may not have as many problems.
Was living the good retired life on the Lake. Now just living retired.
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#28
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
(09-17-2020, 01:09 PM)photobug Wrote: 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?

There's a lot of advice on building workbenches out of borg lumber.
One of the ways to make this work is to start with the larger beams, which tend to be straighter, and then cut to get quarter-sawn pieces.  These will tend to be more stable.

Matt
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#29
  Re: Building out of Construction Lumber by photobug (I am planning on bui...)
(09-17-2020, 01:09 PM)photobug Wrote: 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 use 2x yellow pine lumber frequently for furniture projects.  I buy the widest boards I can,  usually 2x10 or 2x12.  When I get it home, I cut the pieces 2" longer than I need and "sticker" it.  Stickering just means you stack it with 1"x1" boards between layers so air can flow all the way around the wood.  I have a moisture meter, but sadly I don't use it.  Usually by the time I can get back in the shop, I assume the wood is dry.

On the other hand, I built a loft bed with 4x4 douglas fir legs.  I don't have a power jointer, so I flattened one side with a jointer plane and then made one side square to the flat side.  The douglas fir and all its knots were murder to handplane, especially compared to yellow pine.  I carefully took all the twist out by checking with winding sticks.  By the time I had cut the joints, many of the posts had twisted.  I have never had that much trouble using 2x yellow pine.  The big problem with the 4x4s is that they contain the pith and you can't cut it out. 

Construction lumber is usually less expensive than hardwoods, but during the pandemic, the price of construction lumber in my area has soared.  At the Lowe's near me, a 2x4x8 is $7.21, which is $2.06 a board foot.  A yellow pine 2x12x8 is $28.44, which is $2.53 a board foot.  The last time I bought S3S 4/4 poplar from a hardwood supplier it was $2.20 a board foot.  So during these crazy times, you might not actually save money by using construction lumber instead of hardwood.

Mark
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#30
  Re: RE: Building out of Construction Lumber by Gary G™ (You could buy their ...)
(09-17-2020, 06:41 PM)Gary G™ Wrote: You could buy their kiln dried framing stock

Kiln dried for construction aims for around 19% moisture. Reason is that under ~20% wood wont rot or grow fungus. So that's fine for framing a wall. It will dry and shrink a little, and maybe try and move, but it's nailed into a wall, so it can't move much. 

But as other say, furniture wood should be dry to close to the average level in your house. That could be 6 -14%, depending  on  where you live.  If you build furniture with ~19% wood, and put it in a house with ~8% EMC, then it's going to lose moisture, and that means shrinking and other movement. 

My advice is get a moisture meter, and stack your wood up on stickers, in the environment it's going to live. Point a fan at the stack to speed things up (more air flow = faster drying). Measure the moisture each week and take a note. Here's the thing, the meter doesn't have to meet any exact number, it just needs to have stopped changing. Once it's not changing, the moisture of the wood is correct for that environment. My cheap meter only claims to be +/- 2%. But if wood reads the same as a piece that's sat in the house for a year, then it's probably "right" Softwood dries fast, so we are only talking a few weeks/ 

Other thing is that not all construction wood is the same. "SPF" means Spruce / Pine / Fir, and covers about 30 different tree species. Douglas Fir is better wood than most pine, but that doesn't matter if you are building a house. They are all good enough to hold up a wall.  But if you are building a table, you can get better results with some species.
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