Dimensional Framing Lumber from Mixed Hardwoods

Thoughts on using local hardwood to produce framing lumber for outbuildings. October 4, 2011

If you are going to cut dimensional lumber such as 2x4 or 2x6, and you may or may not use it alongside commercial lumber, do you cut it the same size as the commercial lumber or do you cut it a little larger and allow for shrinkage? Also, is there anything wrong with making dimensional lumber out of the miscellaneous hardwoods that a person runs across? Are there any woods that I should stay away from to make construction lumber for barns and outbuildings or even for home construction? I don't have a pine tree within several hours of me, so I will be choosing from hackberry, post oak, red oak, elm, pecan, hickory, ash - basically all of the hardwoods found in NE OK. I have a solar kiln that I plan to dry the furniture lumber in, but the construction lumber I want to air dry. Any problems here that I need to know about?

Forum Responses
(Sawing and Drying Forum)
From contributor A:
Yes! While hickory, pecan, hackberry, and elm can and have been used, they would not be my first choice for framing lumber. The post, red, and white oaks and ash will do fine if sawn correctly for framing and timbers. Also eastern red cedar will work and you should have plenty of that around you.

I saw 1 5/8 thick x 4 or 6 and then air dry. I may plane it to 1 1/2 and run through the table saw to cut it to width if matching store bought. Most of the time I use it the way it comes off the saw. Sawing the grade off the sides and cutting the heart up into 2x6's works fine. I own a house in town that was made in 1940 and it is all made from sawmill red oak and is as solid and fine a house as any made today.

From the original questioner:
Thanks. I don't know how much home framing I would be doing, but I do plan on building some more outbuildings and would love to use the less common hardwoods if possible. What you described was pretty much what I was thinking. If I'm not mixing it in with commercial lumber, it doesn't really matter what size it is exactly, as long as it's the same in what I'm building. Thanks for the info.

From contributor D:
I'm a forester in NE OK. There is pine around here. Where are you talking about?

From contributor S:
For the construction lumber, cut to a size you like and just stay with that. Air drying works fine (it was done that way and still is being done that way), unless you have insect problems.

The pros of cutting nominal:
- construction materials such as nails, strong ties, windows, doors are all made with those dimensions in mind
- you'll get more boards per log.

The cons of cutting nominal:
- not as strong
- not a construction standard
- more sensitive to setwork errors

From contributor P:
I've been cutting ash and hackberry for framing lumber for my own use, to build outbuildings just like you're talking about. I've been sawing 1/8 over just in case I have to buy conventional lumber to finish. It's been pretty close so far. I had to drill holes for screws after it air dries for a year.

From Professor Gene Wengert, forum technical advisor:
All conventional commercial construction lumber will have a stamp on it indicating the MMC at which it was made (maximum MC). The size at that time is the same everywhere, such as 1.59" thick. For example, if S-GRN (meaning surfaced green, so there is no MC guarantee), then when such lumber dries to 10% MC in use, it will no longer be 1.50", but will be perhaps 1.43" thick. If the piece says KD15, which is under 15% MC when planed to size, it will change to 1.49" in use. So, go to your source for commercial lumber and see what they are selling. Then, figure the estimated size in use. Then add about 5% in size to the width and thickness. Length is not changing.

From contributor T:
Cottonwood makes excellent framing lumber also and is usually overlooked due to its poor reputation regarding durability in moist conditions. As long as you keep it dry, cottonwood makes excellent framing and interior paneling. Also great for cabinet shelving or even carcass work if you have more cottonwood trees than money to buy sheet goods.

I realize you didn't list cottonwood, but most guys just never consider it so you may not even be aware you have them? Plus, cottonwood takes a nail 10 times easier than pecan, oak, and most others you named, and it does not tend to split like other species when nailed near the ends. Once dry it's very light. Drying it can be a problem because it dries about as fast as ERC, but unlike that very stable species, cottonwood wants to collapse as it dries. It's one of the more watery species and could be called waterwood instead of cottonwood. I reckon it's called cottonwood because it's so light once dry.

I'm referring to eastern cottonwood. Also be aware that it isn't a great species to bear a lot of tension, so stud walls and lightly loaded joists or rafters are okay, but you should forget about post and beam or timber frame unless your design limits any horizontal members to short spans. If you know its limits is can be a great resource for all around construction. As you can tell I love the species so I may be a little biased.

From the original questioner:
Thanks. I got the news that I was hoping to get. Is there any wood out there that is just not worth messing with? I won't be making ties or pallets or anything like that. From what I can tell by my research, its seems you can get a little use from most woods.

From contributor W:
Like you, I like to use almost all species of wood. After sawing a great diversity of species, I came to realize why commercial grade markets exist for the oaks, walnut, yellow poplar, ash, and cherry where most of the other species are used for crates and pallets, etc.

The spiral grain woods like blackgum, hackberry, sweetgum, sycamore, and the elms are tough to dry straight without a kiln, as I only air dry. I have experienced much more drying degrade, warp, and twist with these woods. I would not use these woods in a framing application where I wanted straight walls or flat floors. You may have better luck kiln drying it and have a different experience.