Lumber Quality Grades

Hardwood lumber is used to make flooring, furniture, cabinets and decking. Softwoods are used for framing, trim and other purposes. So it's important to understand these differences when buying lumber.

Hardwoods come in a wide variety of colors, and they range in hardness (learn about the Janka hardness scale) which is why you need to research hardness when buying flooring.

Learning About Hardwood Lumber

Hardwood lumber comes from deciduous trees with broad leaves, that generally go dormant in the winter. There are hundreds of hardwoods like oak, ash, cherry, maple and poplar, that thrive in North America's temperate climates. Each has different grain patters, texture and color which is why the choice of flooring and cabinets is so difficult.

There are also tropical hardwoods like mahogany, rosewood, teak and wenge, that are not native to North America. They're found in tropical forests around the world, and must be imported. Their color, grain patterns, hardness and luster differ from those of American hardwoods but don't get fooled by pseudo hardwood lumber, that's really wood you've never heard of.

Bamboo is also gaining popularity as a green flooring alternative, and it's sometimes referred to as a hardwood. However bamboo is a grass and not a hardwood.

Hardwood Lumber Sizes

When you buy hardwood at Home Depot of Lowe's, the actual dimensions will be the same as softwood (click to view this chart). When you buy hardwood lumber at an actual lumber yard, the dimensions are smaller than when the wood was cut, but only slightly as lumber yards typically only finish one or two sides, leaving the others rough.

The thickness then depends on how many sides have been planed, so the hardware lumber sizes in the chart below are for hardwood surfaced on one (S1S) or two (S2S) sides. In contrast, the hardwood you buy at Lowe's or Home Depot has been surfaced on all four sides (S4S).

Some lumber yards sell lumber by the board foot. A board foot is a measure of the thickness, width and length of lumber that reflects the number of sides that have been milled (planed). Here's a calculator to help you calculate the board feet you need to buy.

Learning Softwood Lumber Grades

Softwood sizes are similar to hardwood lumber. Softwoods like pine and fir are graded based on their strength and/or appearance. Most framing lumber which is two inches thick, is graded for it's strength as it's hidden behind the walls covered by drywall. Softwood lumber that is used for finish work that isn't painted, is graded based on knots and other visible defects.

The common grades found at your local lumberyard from best to worst are: