Because our father was in the business, lumber yards were as familiar to us as kids as grocery stores or gas stations. We've discovered, however, that most people have had little exposure to lumber and lumber yards and thus are uninformed on how to decide on what lumber to use for what job.

You may not be aware of it, but board and dimensional lumber are usually sold in lengths that vary in increments of two feet. This is because lumber mills choose to saw lumber in even lengths in increments of two feet (10, 12, 14, 16, 18 feet, etc.). This doesn't mean, however, that you can't buy boards in odd-numbered lengths. For example: If you want two 7-foot lengths of material, the lumber yard will cut them from one 14-foot piece. If you want just one 7-foot length, you might end up paying for an 8-foot length. So, plan your project wisely.

Shorter lengths are less expensive than longer ones. If a longer piece provides better appearance or improved structural integrity, by all means pay for it. But, don't buy long lengths for a job that will ultimately result in them being cut into shorter pieces.

Also, don't be disappointed if you ask for a two-by-two and get a piece of wood that is one and a half inches square instead of two inches square. Rough surfaced lumber is usually available in nominal dimensions (a 4x4 is actually 4 inches square). Fence material is a good example of rough lumber. Surfaced or finished lumber is not nominal in size. Once it has been sanded smooth it gets smaller. For example: a finished 4x4 ends up being 31/2 inches square, reduced from its rough dimension of 4 inches square. This is true of most surfaced boards and dimensional lumber.

Wood specie is also important for many reasons. For example: Douglas fir is great for structural work. Although it is much stronger than some other woods, it is much harder to saw and nail. Redwood, on the other hand is soft and easy to nail, but doesn't have the strength that fir does. However, redwood does contain natural oils called tannins that help it resist damage by water and insects. Pine is excellent for shelves, furniture and trim material, and it also has the strength for walls, although it is not as strong as fir. By the way, "pine" is used to refer to many different species of wood such as sugar pine, ponderosa pine, white pine, southern yellow pine and many more. Cedar is ideal for exterior use. Like redwood, cedar contains elements that help it to resist damage from insects and it also is resistant to decay.

Pressure-treated (PT) pine and fir are good for exterior use. Pressure-treated fir is great for deck framing. It combines the strength of Douglas fir with the decay resistance of redwood. We suggest not using pressure-treated material for the actual deck boards for several reasons:

It is hard to nail, it tends to splinter where redwood won't, and you might discover that you are allergic to the poisons used in the chemical that is used in the pressure-treating process.

Be careful when shopping for redwood. Redwood prices range from expensive to more expensive. Redwood cut from the center of the tree (heartwood) is the reddest, and the most decay-resistant. At the outside of the tree the wood gets whiter and less resistant to decay. The white wood in redwood is called sapwood. If you buy redwood that contains a lot of sapwood, it's a good deal for the store owner, but not for you.

Once you have decided on a specie, you will need to select a grade within it. With fir depending on size you can choose from select structural, 1, 2, and utility. Utility is the lowest grade. With redwood, heartwood is best and merchandise "merch" is cheapest. With Cedar, grade A is better than grade B. Stud grade in pine and fir is a cheaper cut of wood that is usually available only in one or two common wall-framing lengths.