Author Box
Articles Categories
All Categories
Articles Resources

Buying Dimensional Lumber at a Home Center: How to Avoid Cup, Bow, and Crook

February 21, 2012 | Comments: 0 | Views: 166

The best way to avoid trouble when building a wood project is to start with lumber that is straight, flat, and square. Of course, woodworkers who own expensive shop tools have a definitive advantage in battling the most common types of lumber defects. A nice wood planer, for example, can transform an otherwise crooked and twisted board into a perfectly straight piece of lumber - if you have the cash ($500+ for most models). Is this a practical investment? Maybe not, if all we're talking about is building a few simple projects from pine. Not to mention that a lot of woodworkers avoid using their planer with pine, for fear of gumming up their expensive blades with pine sap.

That leaves the rest of us with using the best boards we can find from the aisles of our favorite home center. The inherent problem here is that most of the lumber shelves at a big box store are riddled with boards that are warped and twisted. Not so much of a problem for carpenters who build houses and garages (there are workarounds for using warped lumber), and it's not really a problem for the home centers either, since a good chunk of their business comes from the construction industry, not woodworkers. So the challenge for small-project builders is to figure out how to dig through the piles and pull out the best boards in the stack.

The Good, Bad, and Ugly - What to Look For When Sorting Lumber

Once you have a reasonable system in place for digging through the massive stacks of lumber, the next step is to carefully examine each board for signs of cup, bow, crook, and twist. Here's what to look for.


Boards with cup have a "U" shape from edge to edge, and are nearly useless for building anything. Why? Edges are where boards come together to form a joint. If a board is not super-flat along that edge, the joint won't work - believe me, it just won't. So the best way to check for cup is to lay the board flat on the floor and check for a side-to-side rocking motion. Then flip it over and check the other side. If it doesn't pass the test, send that board to the bad cart.


Bow is easy to spot. It's the same kind of "sag" you might see in an old bookcase shelf that's been loaded with too many books. The best way to spot bow in lumber is to hold the board edge-side up, close one eye, and then peer down the full length. If you don't see a straight line, the piece is warped from one end to the other. A certain amount of bow might be okay, though, especially if you plan to cut the board in small lengths. However, if you need the full length - for projects like a workbench or picnic table, send it to the bad cart and keep looking.


Unfortunately a board with zero cup and zero bow can still be crooked. Best way to spot crook is to hold the board surface-side up and peer down the full length of the board. A severe case of crook makes an otherwise straight board look like a road with a curve. Unless you plan to cut this board into a lot of smaller pieces, send this one to the bad cart and keep looking.

Other Lumber Defects to Watch Out For

Twist & Warp

Sometimes lumber defects are uneven and scattered. For example, you might find a board that is perfectly square at one end, but cupped on the other. Or maybe you'll find a board that is surprisingly straight through most of its length, but then starts to curve a little towards one end. Although you might be tempted to quickly discard these boards, it might be worth your time to take a second look. Most project pieces call for relatively short lengths of lumber, which you can cut from anywhere on a board. That means not every board you bring home necessarily needs to be perfect (in fact, you will have trouble finding perfect pine lumber in most home centers). The best approach is to bring your project design with you, and then look for boards that can yield just enough flat and straight pieces for the project at hand.


The word "check" is woodworking lingo for a split that appears at the end of a board, which can sometimes happen as lumber dries out. These boards can still be useful, as long you don't need the entire length of the board for your project. Simply trim enough length off the end of the board to remove the split, and you're set to go.

Knots & Voids

Pine can be riddled with knots and voids, especially in the less-expensive grades sold at home centers. The amount of trouble these kinds of defects might cause depends a lot on where they are located on the board. For example, a pine knot that is situated somewhere near the center of the board doesn't really trouble me. In fact, it can even be nice decorative touch to the overall design, depending on the type of project you are building. However, I'm quick to reject boards that have knots and voids along the edges. This is a bad location for defects, because it's exactly where we'll do most of our joinery. Go ahead and buy the board if you can extract enough pieces with clean edges on both sides, otherwise set the board aside and keep looking.

A Final Note on Safety: Wear Gloves!

Getting a 3-inch splinter lodged in your palm while shopping for lumber will quickly bring your wood project to a screaming halt. Take my word - it's not worth the risk. Always wear gloves when sorting through lumber. And if you're not worried about splinters, then do worry about all the other sharp edges in the lumber aisle that cause just as much (or more) damage - like staples, metal banding, and sharp corners on warehouse shelving.

Andy Duframe is owner and creator of, a website that explores the basics of woodworking, with an emphasis on helping beginners learn the fundamentals of designing and building simple wood projects. Andy is the author and designer of the 10-part eBook series "How to Build Anything - with 3 Tools, 3 Boards, and 3 Steps."

Source: EzineArticles
Was this Helpful ?

Rate this Article

Article Tags:

Home Center


Dimensional Lumber


Best Boards


Buying Dimensional Lumber


Lumber Defects


Softwood Lumber

There is different types of locksmiths available to install, maintain and repair locks and keys. Here in this article, we are going to discuss four major types of professional locksmiths. The most

By: jamescor l Home Improvement > Security l April 03, 2013 lViews: 563

Another point to note is that the leather sofas can come both in contemporary and traditional designs. Indeed, the traditional Chesterfield sofa. Another point to note is that the leather sofas can

By: Simon Liva l Home Improvement > Furniture l December 23, 2012 lViews: 260

A bathroom is not simply a room in the house for you to bathe, get dressed and do the usual necessities. Today, the bathroom is where you unwind and relax from all the anxiety of the day. For this

By: jhon ford l Home Improvement > Bath and Shower l December 23, 2012 lViews: 273

These bathroom designers know and understand your requirements and have the power to convert your imagination into reality. These bathroom designers know and understand your requirements and have the

By: Simon Liva l Home Improvement > Bath and Shower l December 23, 2012 lViews: 1189

Having the baby furniture ready before your baby comes is not only practical but makes the choosing and designing of the baby’s room fun. The reason for this is that you can take a longer time in

By: Leanne Smith l Home Improvement > Furniture l December 14, 2012 lViews: 284

With a team of professionals around, you don’t need to worry about the health of the carpet. A Professional carpet Melbourne Company refrains from using harmful chemicals to accomplish their task.

By: Simon Liva l Home Improvement > Cleaning Tips and Tools l December 12, 2012 lViews: 445

As there are garages in simple design, there are also those that can be constructed having several storage kinds. An example of the latter can include one with an attic. In constructing an attic in a

By: Salvador Bentonl Home Improvement > DIYl July 03, 2012 lViews: 189

Want to do your part in making the world a little bit better and save yourself some money as well? How about turning yard waste and kitchen scraps into organic fertilizer. You'll be saving space in

By: Giuseppe Guariscol Home Improvement > DIYl July 03, 2012 lViews: 178

When you walk into your home, does the look and feel of its style make you want to just walk back out? If you are tired of your home's current decor, but your budget won't allow you to remodel or

By: Robin Halel Home Improvement > DIYl July 03, 2012 lViews: 216

It may be summer now, but chances are you are already thinking of the many home improvement projects you have to complete before winter arrives. You have all the tools, the industrial fasteners, and

By: Robin Halel Home Improvement > DIYl July 03, 2012 lViews: 172

When choosing different types of ceramic floor tiles and porcelain floor tiles is extremely important that you get the right type to suit your property and needs. The reason is because when

By: D. Harrisl Home Improvement > DIYl July 02, 2012 lViews: 221

When it comes to flooring, polished concrete floors are great materials, which are more commonly used. However in homes it's not something you would want to leave unfinished or uncovered. Many people

By: Wanda Arnoldl Home Improvement > DIYl July 02, 2012 lViews: 208