Frequently Asked Questions: Lumber

1. What are Hardwoods and Softwoods?
2. Why does bird's eye occur in different kinds of wood?
3. The dimensions of rough cut lumber determine the lumber's nominal size. This can be misleading to a novice when lumber is referred to in sizes which are not the actual dimensions. So how does it work?
4. Is it better to paint a big project piece by piece or as a whole assembled together?
5. I've been building furniture, mostly out of pine, and I've been very disappointed to find that after a project is finished the joints become loose and some of the pieces no longer fit properly. I suspect that it has something to do with humidity. What do I do?
6. When did chestnut trees disappear?

1. What are Hardwoods and Softwoods?

The degree of hardness has no bearing on whether the wood is a hardwood or softwood. Hardwood was the lumber cut from deciduous or broad-leaved trees that produce enclose seeds such as cherry, maple, walnut, aak, etc. Softwood was the lumber cut from coniferous or needle-bearing trees that produce free unopened seeds such as the cones of fir, cedar and pine.

2. Why does bird's eye occur in different kinds of wood?

It hasn't been proven conclusively what the actual cause is, however it is known that it only occurs in trees which undergo growth stress from competing with surrounding trees for light and nourishment. Studies have shown that a tree which has developed bird's eye at an earlier stage of its life will no longer develop the figuring in future growth if the trees around it are cut down. Nearby maple trees that also developed bird's eye continued to do so if the neighbouring fauna was left undisturbed.

3. The dimensions of rough cut lumber determine the lumber's nominal size. This can be misleading to a novice when lumber is referred to in sizes which are not the actual dimensions. So how does it work?

After surfacing, a board might be reduced by as much as 1/4" on each side but it will still be identified by the nominal width. This is the erosion a nominal 2" x 4" board, a "two-by-four", is actually only one and one half by three and one half inches in size. Here are the nominal and actual sizes for most common lumber: A nominal 1" x 2" is actually 3/4" x 1-1/2. A nominal 1" x 6" is actually 3/4" x 5-1/2"; a nominal 2" x 4" is actually 1-1/2" x 3-1/2". Most construction lumber is supplied in lengths of eight, ten, and twelve feet.

4. Is it better to paint a big project piece by piece or as a whole assembled together?

Piece by piece is always the best way to get full coverage and to avoid painting around hardware, etc.

5. I've been building furniture, mostly out of pine, and I've been very disappointed to find that after a project is finished the joints become loose and some of the pieces no longer fit properly. I suspect that it has something to do with humidity. What do I do?

Wood is an organic substance and expands and contracts with changes in humidity... always has... always will! The secret is to work the wood only after it has adjusted to local conditions. Every workshop should be equipped with a storage area where wood can be air dried. Wood should be purchased well in advance and its moisture content should be in a 7 to 12% range. You can usually be assured that the wood is not to wet if it is sold as "kiln dried", however even then it is a good idea to let it air dry in your shop for a while. Following these procedures should minimize shrinkage and splitting.

6. When did chestnut trees disappear?

Chestnut blight has devastated North American stocks over the past 20 years. Wood from infected trees is of no commercial value. In an effort to contain the spread of the disease there are severe restrictions on the cutting and transportation of the timber.