Buying Lumber

Regardless of the type of wood, and whether it has been seasoned or treated, make sure you know whether your supplier is selling it by its rough-sawn or its planed size.

Rough-Sawn Wood vs. Planed Wood
Wood may be supplied either rough-sawn or planed (smoothed on all sides). This can make buying it confusing because lumber is usually priced and sold according to its dimensions when it is first cut into rough-sawn lengths. Rough-sawn lumber is therefore close to the size stated when you buy it, although it may be slightly smaller due to shrinkage during the drying process. But planed lumber is smaller than its labeled size, because it has been smoothed with a plane on all sides. When you go to your local lumberyard to purchase lumber, you'll need to know their actual sizes.

Rough-Sawn Wood
Used where it will not be visible — in a stud wall, for example. It will be close to the size quoted, because lumber is measured when it is rough-sawn.

Courtesy of DK - Do It Yourself Home Improvement © 2009 Dorling Kindersley Limited

Planed Lumber
Used where it will be visible, such as for a baseboard. It may not be the stated size, because wood has been removed from every face to give the smooth finish.

Courtesy of DK - Do It Yourself Home Improvement © 2009 Dorling Kindersley Limited

Green sources of lumber

Sustainable Wood
The most important issue when buying new wood is to know whether it has come from a sustainable source. Lumber from recognized sources usually bears a stamp, such as that of the internationally recognized Forest Stewardship Council — a not-for-profit organization that promotes the responsible management of forests.

Reclaimed Lumber
Reclaimed wood has the advantage of being thoroughly seasoned, and may look more appealing than new lumber. However, some of it may be unusable, so check for damage when buying.

Checklist When Buying Lumber

- Make sure that the wood you are buying comes from a sustainable resource.
- Find out how it has been treated and seasoned, and how it has been stored.
- Check lengths to see if they are bowed or warped, are split, are damp, or contain excessive or dead knots.
- Find out whether the quoted sizes are nominal or actual, so that you get the correct quantity of lumber.
- Ask if the supplier will deliver to your home. This can be useful if you require a large quantity and/or particularly long lengths. Check lumber carefully when it is delivered.

Recognizing Problems

When buying wood, look out for splits, knots, and uneven grain. Splits can occur naturally in wood due to shrinkage or growth defects, but it is more likely that the wood has been dried too rapidly or the planks stored incorrectly. Softwoods damage and warp more easily when being stored. You will pay more for defect-free wood, but it is worth examining lumber thoroughly before purchasing.

Warped Lumber
Bent or twisted wood is difficult to saw accurately. Bending is usually caused by stacking or otherwise storing wood badly. Bowed or warped lumber may have unseen stresses due to the twisting. Look along the lumber for signs of bowing or warping.

Knots
In rough carpentry, knots, shown here, are hidden and don't matter. They may spoil finish carpentry by bleeding (especially on softwood) or showing through paint. Treat them with knotting solution first.

Courtesy of DK - Do It Yourself Home Improvement © 2009 Dorling Kindersley Limited