Question
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.
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
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.
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.