Wide Construction Lumber for a Workbench

I get this question a lot ever since building my Nicholson inspired workbench.

workbench02

Has your workbench exploded yet from the twisting and warping that has undoubtedly occurred as a result of your use of those wide construction grade boards?

OK. So maybe the questions aren’t worded exactly like that. But I do get a lot of questions about using wide construction grade lumber for a workbench and how to prevent the resulting bench from self destructing. Personally I think this concern is a bit over hyped, but there are some things you should do when building your bench to make sure you don’t have too many problems down the road.

The #1 trick to using wide 2X construction boards for a workbench is to make sure they are dry before you use them. The construction grade 2X stock that many home centers carry is not kiln dried. This means that the miosture content of that stock is going to be very high. Too high to work with right away. If you can, find a supplier who sells 2X stock that has been kiln dried. I was able to buy kiln dried 2X stock for my workbench. So once I brought the boards into my shop and left them stickered there for a couple of months, I could be sure they wouldn’t move much after building the workbench. Since the boards will stay in the shop after the bench is built, the best place to equilibrate them is in the shop space.

If you are not blessed with a supplier in your area that sells kiln dried 2X material, all is not lost. You will simply need to let the boards sit and dry for much longer than you will with kiln dried stock. Bring them into your shop, stack and sticker the boards, and let them sit for several months. Check the moisture content once every week or so and don’t work with the boards until the moisture content stays relatively constant. After they are dry, you may have to re-flatten them, but if you chose your boards carefully, you may not have to flatten them much, if at all.

That brings me to tip #2 for using wide construction grade timber for a workbench. Choose your stock carefully. Even if your stock is kiln dried, but especially if it is not, you want to choose boards that were sawn as close to the center of the tree as possible. This will give the board the greatest amount of “quarter sawn” grain as possible. Wood moves the most in a direction that is tangential to the growth rings. This causes flat sawn boards that are close to the bark (those with near horizontal growth ring patterns on their ends) to cup severely when they move. However, boards sawn close to the center of the tree will cup much less, even if they were not kiln dried. After the boards have sat in your shop for several months, choose the ones that have cupped the least to use for the aprons and top boards. Those with the most cup should be ripped into narrower boards for use as stretchers and cross bearing braces for underneath the top.

This brings me to tip #3. Use the absolute widest and longest boards you can find. Wide, long boards need to come from wide, tall trees. In addition, the widest boards are sawn from the areas of the log that are closest to the center of the tree. Don’t try to save money by purchasing 2x4s for the stretchers and cross bearing braces. These boards are likely to twist and warp on you. These benches are inexpensive enough to build from wide stuff. Trying to save another $10 by buying 2x4s instead of 2x12s will make you curse construction lumber workbenches. Get all of your parts from 2x12s, and the longest ones you can get at that. If you can find 20 footers, they are likely to be flatter and straighter than 8 footers. The bench will cost you a bit more, but you’ll be happier and have a bench with fewer knots in the end.

With workbenches made from DRY construction grade lumber, once everything is assembled, movement is actually very minimal. Contrary to popular belief, softwoods like pine, fir and spruce are extremely stable, when they are dry. Softwoods get a bad reputation for being unstable because they are usually still wet when they are purchassed. Construction lumber is not typically dried to the same level as hardwoods for fine woodworking (at least not here in the States). So as the wood continues to dry, it will typically move. However, once it has been dried to the same level as the hardwoods typically are, most dry softwoods are actually more stable than most dry hardwoods. So the #1 factor in getting a good, stable and flat workbench out of softwoods is to make sure they are adequately dried before you start building with them.

I built my workbench several years ago and have been working with it regularly ever since. It does not have any kind of finish on it, so it is fully exposed to all the humidity swings that occur during the year. I have needed to re-flatten my workbench top exactly one time since building it, and even then, it had moved so little and was so barely out of flat, that it took me less than 10 minutes to do the job. I have no doubts that constrution grade lumber can make a fantastic workbench. With just a little up front preparation, you can have a workbench that will last you several generations without spending a fortune. Being built of construction grade lumber, I am also not afraid to ding it up, scratch it, spill stain on it, drip glue on it or hurt it in any way. I treat it like a workbench, not a piece of furniture, and I know I can replace the top for $20 if it ever gets too far gone. So don’t fear wide boards. Wide boards are your friends.

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10 thoughts on “Wide Construction Lumber for a Workbench

  1. Hear here! Exactly!
    Even though I didn’t wait as long as you prescribe for drying home center lumber, my 12 foot Nicholson bench is serving very well. Nor, did I use 1x12s. At my home centers, all of those were as bad as the 2x4s. The 1x8s were much better.

    Oh yes, one board developed a crack about a year after the bench was built (coincides with some dog holes … hmmm). A few ounces of epoxy and a quick planing fixed that. All the other boards have developed various dings and stains, but the danged thing still works as a workbench. 🙂

  2. Great post Bob! Its timing couldn’t be more perfect. I have several constuction grade 2×12’s (16 & 10 footers) sitting in my shop right now drying. I have two questions that you may be able to help with:

    1) How do you know when the lumber is dry enough to begin working? I’ve heard that taking the temperature of the face and end grain of the boards is a fairly good way to tell (since more evaporates out of the end grain, when the temperature is the same the board is likely at equilibrium with the shop). Are there any other techniques you would recommend?

    2) How much does the temperature changes in a shop affect wood stability? During the winter here, my shop may drop to 35 degrees farenheit at night and maybe back up to the 50s during the day. During the summer, it may be 80 or 90 in the shop on the hottest days and down into the 60s or 70s at night. Fortunately, I live in a very dry area so I don’t have to worry much about condensation forming on my tools, but I’d like to mitigate the movement of my material as much as possible. What advice would you give for someone in my situation*?

    Nate

    * – I’m looking into doing better insulation and climate control in my shop, but there is a good chance that project will be a few years out.

    • Nate,
      Moisture meters like this one are your friend when you work with stock that has not been kiln dried. Check the moisture in the wood once every week or two and record the reading. When the reading more or less stays the same between several checks, the wood is ready to go. It may take two weeks and it may take several months depending upon the initial moisture content in the wood and the environmental conditions. By checking once or twice a week before you get started, you’ll know when it’s ready to work because the moisture content really won’t change much between readings.

      As for climate control issues, temperature doesn’t matter. What matters is the humidity. Cold air holds less moisture, so cold days will naturally be less humid, even in dry climates. In areas where the climate is relatively dry, like the southwest, temperature swings will have little influence because the temperature swing will not be accompanied by a large change in humidity unless it goes from sunny and cold to rainy and warm. In the northeast, however, where the humidity swings can be very large, temperature swings can be very indicative of drastic changes in humidity.

      As I said though, once the wood is dry enough to work, after the bench is built, the softwood will not move all that much. Dry softwoods are surprisingly stable.

    • Nate,

      Another way to check the drying process on boards is to weigh them. If it isn’t too much of a pain to balance them on a bathroom scale, weigh them every few weeks. Keep a running log by writing down the weights on each board with a piece of chalk. It will decrease in weight as it dries, and once the weight stays constant over several readings, it’s a good indication it’s reached equilibrium with your shop. Following up with a moisture meter at that point is a still a good idea, though.

      -Eric

  3. The last bench I built the I let the lumber sit all of about a week. I wasn’t overly fussy about the planks other than I wanted them to not be twisted and too knotty. I put all of the planks bark side in when I build so if they warp it isn’t as noticeable and any warp is easier to control. The great beauty of this type of bench is that you flatten the frame below the top before you attach the top to it. This minimizes the amount of work you need to do on the top. I glue and screw the front edge down for about the first 4 inches in width, I them screw the back edge down. This allows for a bit of movement. I sink the screw heads by about a 1/4 inch. I don’t flatten the top until the bench has sat about a month. This last one is about the 14th bench we have made. My first one cracked a bit at the far end due to an excessive mallet blow. The crack is of no consequence. The last bench cost all of $70 for materials. We gave it away at a Minnesota Woodworkers Guild meeting.

  4. Great post Bob,

    When I built my first bench back in the late 90’s there were few books on building workbenches, not like there are today. Nor, was there any internet talk about them. It was just something you did as a necessity for building furniture in a wood shop.

    I built my first bench, similar to a french bench, but made it from lumberyard 2×4, and 2×6 Douglas Fir, I did spend considerable time digging though the old lumberyard’s (now long closed) bins. It’s still a solid bench today. I sold it to a friend after 10 years of hard use.
    Never any checking, or twisting of any kind. My shop floor wasn’t sealed, so about ever year or two I would have to trim a leg to bring it back to sitting flat.

    I do think the key to building a bench from any type of lumber is, as you make note of, the dryness of the material, and to sticker it and let it acclimate to it’s new surroundings.

    Sam

  5. You’re dead on with the construction lumber as far as I’m concerned.

    A few years ago before I know to look at the grain of the wood I bought a pair of 8′ 2″x12″ boards to use as ramps. What had been very straight boards at HD turned slightly twisted and cupped over the following months. Still good for what I use them for, not not bench material. The next large boards were a pair of 20′ 2″x10″ boards stored outside at the lumberyard with rainwater standing on them. I just took the top two off the stack and they looked fine for about a month, then one of the took on a significant twist about 1/3 of the way along it’s length. The other board stayed flat and I could have cut up a lot of nice boards out of it. Just by looking at the grain you could see why they reacted differently as they dried out.

  6. Thanks for all this advise. I’m so glad I took the time to investigate a little deeper into this for my future bench. I accessed this on impulse from woodmagazine site post.

  7. I see you used the flat side of the board for the top of your bench. How thick is your bench? Also, if you were going to do a 4″ thick top, would you still buy 2 x 12s or something else since they would be ripped to width?

    • My workbench top is 1-1/2″ thick. I’d prefer it be a full 2″, but it works. If I were going to build a bench like the Roubo with a thick, unsupported top, I’d seek out the widest 12/4 or 16/4 boards I could find and build the top from them. Preferably a pair of 12″ wide boards. I would not buy construction lumber for this kind of a top because I don’t like to laminate boards. So I’d spend the extra money for some big 16/4 boards.

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