Introduction: A Photographic Guide to Selecting Lumber

Picture of A Photographic Guide to Selecting Lumber

If you have spent any time in the lumber section of a home center, you have probably seen people digging through piles of 2x4s, pulling out one at a time, and peering down its length to determine its quality. With this instructable I hope to save you time while also helping you select the best wood for any project. All of the information used here can be found in Wood Handbook: Wood as an Engineering Material published by the USDA, which can be freely accessed here. I will attempt to pare down this 500+ page book into a brief, but useful, instructable for selecting wood.

Note: while most pictures herein depict cedar, these rules apply to any wood. I chose to use cedar for two reasons: first, its characteristics are usually well defined, making it a good sample for this photographic guide, and second, the stock of cedar at the store had the best lighting for taking pictures.

Please note, you have to click on the individual pictures to see all the notations! Also if you like this please vote in the 2x4 and epilogue laser contests! Thanks!

Step 1: Things to Avoid

Picture of Things to Avoid

The Pith:

The pith is the center of a tree, easy to spot by looking at the base of a 2x4 for a) a full circle or b) a tightly curved grain, indicating that lumber was cut close to the tree's center. The pith is very hard and brittle, prime conditions for cracks to form.

Sapwood:

Sapwood is the outermost few growth rings of the tree, and depending on the type of wood this can be difficult to identify. It tends to be easier to spot in darker woods, but can be difficult in lighter wood like pine.

This wood is softer and weaker than pith or heartwood, and rots more quickly than either if wet. While Sapwood's increased malleability is a potentially positive attribute, it should generally be avoided for most projects.

Changes in ring direction:

This is not always bad, in facts sometimes this can lead to interesting grain in the board, however it can also potentially lead to twisting in the board, however if you are looking for a purely structural board and don't care about how it looks I would avoid boards with different rings orientations.

Avoiding these things should result in you easily finding fairly straight boards.

Step 2: Things to Look for

Picture of Things to Look for

Heartwood is simply wood that does not contain the pith or sapwood. It is the strongest and most stable part of the tree and boards made of heartwood can be milled in one of the three following ways:

Flat-Sawn:

This is the most common type you will find, characterized by the rings being anywhere from perfectly horizontal up to 30º from horizontal. These boards look like what you imagine a typical wood board to look like, and should remain fairly flat. Flat-sawn wood may cup a little bit but it should be minor.

Rift-Sawn:

Rift-sawn wood is any piece in which the rings are at about a 45º angle from horizontal (30º to 60º is considered rift sawn). Again as long as this is heart wood this should remain fairly flat. Visually the grain of a rift-sawn board is very straight, depending on the look you are going for this can be very desirable.

Quarter-Sawn:

Quarter-sawn boards are ones with vertical rings (or 60º to 90º). These boards are the most stable, this is because wood expands more with the rings than it does across them*, this makes these boards ideal if you are planning on gluing multiple of these boards together. Visually quarter-sawn wood can be very attractive. For some woods quarter-sawn doesn't have a distinct appearance but woods like white oak are prized for their appearance when quarter-sawn.

*A more full description of wood expansion can be found starting on page 84 of the linked pdf along with specific expansion rates for different species of woods.

Following the rules in step 1 should get you fairly straight and flat boards, adding the rules in this step should give you the exact board you want.

Comments

patdoherty (author)2016-01-17

Please note, you have to click on the individual pictures to see all the notations! Also if you like this please vote in the 2x4 and epilogue laser contests!

Sandray123 (author)patdoherty2016-02-02

If I might add couple things that could be helpful.

Tip 1: Is that wood expands and contracts from moister in the air
and direct sunlight. The greatest movement, will be at 90 degrees from
the grain direction. Example; grain that runs vertically, the greatest
wood movement will be in the horizontal direction.

Tip 2: End
grain (end of the piece of wood) absorbs moister quicker than the long
or face grain of a piece of wood. So the ends will contract and expand
quicker that the rest of the wood and split first typically. If the
wood is going to sit for a while, may consider sealing the end grain
with one of the following, paint/wax or some type of finish like
lacquer/urethane.

patdoherty (author)Sandray1232016-02-02

Yeah these are great tips and I could think of tons more too, I wanted
to keep this instructable as basic as possible, but I have already
started to work on a sort of advanced version of this instructable,
going more into the specifics of expansion rates and how to deal with or
allow for wood movement, it is a pretty dense topic though, hard to
make understandable.

patdoherty (author)Sandray1232016-02-02

Yeah these are great tips and I could think of tons more too, I wanted
to keep this instructable as basic as possible, but I have already
started to work on a sort of advanced version of this instructable,
going more into the specifics of expansion rates and how to deal with or
allow for wood movement, it is a pretty dense topic though, hard to
make understandable.

patdoherty (author)Sandray1232016-02-02

Yeah these are great tips and I could think of tons more too, I wanted
to keep this instructable as basic as possible, but I have already
started to work on a sort of advanced version of this instructable,
going more into the specifics of expansion rates and how to deal with or
allow for wood movement, it is a pretty dense topic though, hard to
make understandable.

patdoherty (author)Sandray1232016-02-02

Yeah these are great tips and I could think of tons more too, I wanted
to keep this instructable as basic as possible, but I have already
started to work on a sort of advanced version of this instructable,
going more into the specifics of expansion rates and how to deal with or
allow for wood movement, it is a pretty dense topic though, hard to
make understandable.

RasheedA3 (author)patdoherty2016-01-19

I think you should mention this in the instructable. Can you edit?

Anyway, what a great intro to wood selection. Thank you for making the effort!

patdoherty (author)RasheedA32016-01-19

Thanks, I edited it. I hesitated at first to ask people to vote in the instructable itself, I wasnt sure if people would think it was tacky.

MTeodor made it! (author)2016-01-15

Great, to put it here in this way!

TerryN4 (author)MTeodor2016-03-16

I wish all the lumber was as beautiful as this example!

patdoherty (author)MTeodor2016-01-17

Thanks. And thank you for adding it to your DIY wood collection!

MTeodor (author)patdoherty2016-01-18

You welcome! All the best!

skylane (author)2016-01-17

Thanks for putting this up. Wayyyy back, when I took woodshop in Jr High school we learned this along with the "why's of it all".

Sadly, it's now very difficult to find good, quality lumber. That's why you see some guys spending so much time digging through the piles of lumber at the hardware stores and lumber yards. It's difficult to find lumber free of or with minimal knots and hard to find nice "flat" grain as depicted in your picture above.

Mihsin (author)skylane2016-02-02

Giant trees were cut long time ago. Now-adays, trees genes are being manipulated to grow faster, thus becoming softer and subsequently lighter.

patdoherty (author)skylane2016-01-17

Yeah, that is definitely true for woods used in construction like spruce and Doug fur. Although I recently discovered that in the US each state's DNR keeps a list of all the sawmills in that state and you can buy directly from most of the smaller ones. You are then limited to the species that grow in your state but from my limited experience the quality has been great and the prices have been super reasonable.

Old Coot Papa (author)2016-01-18

Great job of reducing a very large book down to a very concise and useful refernce guide. Thanks so much.

patdoherty (author)Old Coot Papa2016-01-19

Thanks, There is still lots more that can be learned from the book but I think I got the most important stuff as far as buying lumber is concerned.

thundrepance (author)2016-01-17

VERY COOL ~ thank-you for sharing this great info! ☻

dmwatkins (author)2016-01-14

Thanks! This is great info!

patdoherty (author)dmwatkins2016-01-17

Thanks! Hope it helps you on a future project.

myrrhmaid (author)2016-01-14

Hubby is always picking thru the wood before he buys it eyeballing each piece now I know what he is looking for! Thanks for the info!

patdoherty (author)myrrhmaid2016-01-17

Glad you liked it!

Test Subject (author)2016-01-17

Great info! Thanks.

patdoherty (author)Test Subject2016-01-17

Glad you liked it.

myhoodlums4 (author)2016-01-17

how cool! way to put it together so it makes sense to the typical layman...... learning something new each day!!!

patdoherty (author)myhoodlums42016-01-17

Thanks! Never stop learning!

WillieJRB (author)2016-01-17

Thanks so much for this instructable. I never thought of what part of a tree different cuts of lumber were actually from, thanks again.

patdoherty (author)WillieJRB2016-01-17

Thinking about how the lumber is cut from the tree has really transformed how I work with wood, I wanted to share that, glad you liked it.

tgimages (author)2016-01-17

Nice simple explanation of a difficult topic.

patdoherty (author)tgimages2016-01-17

That was exactly my goal, thanks!

CAN69Hammer (author)2016-01-17

Thanks for putting the time into this. Very helpful instructable especially for us that loves playing with wood but never really took time to find out the story behind the bark. You got my vote

patdoherty (author)CAN69Hammer2016-01-17

Much apreciated.

Horus9339 (author)2016-01-17

Thank you for such an easy to follow and very educational post.

patdoherty (author)Horus93392016-01-17

My pleasure, glad you liked it.

VladM3 (author)2016-01-17

Very nice instructable. It certainly empowers people to do more DIY woodworking. It's not just about how you finish and use wood, it's also about how you select it (much like with butchering and cooking meat).

patdoherty (author)VladM32016-01-17

Empowering others is always my goal, glad you liked it.

txadams (author)2016-01-17

Geez! My lumber IQ just tripled!

patdoherty (author)txadams2016-01-17

Thanks, glad I could help!

grenstauf (author)2016-01-14

Good stuff, and thanks for the link to the Wood handbook.

patdoherty (author)grenstauf2016-01-15

No problem, it's pretty dense but really interesting!

Kreat0r (author)2016-01-14

highly informative and useful!.
i appreciate you taking the time to write this.favorited :)

patdoherty (author)Kreat0r2016-01-14

Thanks, glad you found it helpful!

About This Instructable

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Bio: I am currently an electrical engineering student with a passion for all forms of fabrication. And I am working as a finish carpenter.
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