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How to Buy Lumber for a DIY Project

Wade Shaddy
Table of Contents

Learn how to identify lumber and wood products for simple DIY projects, with info about where and when to use certain products over others.

Walking into a lumber yard or home supply store might seem overwhelming at first take, but it doesn't have to be. Lumber can be broken down into two categories: hardwoods and softwoods. Most DIY projects -- shelves, frames and structural projects -- can be made with softwoods. More elaborate woodworking projects -- furniture or cabinets -- typically need hardwoods.

Cost and Availability

As a general rule, hardwoods cost more than softwoods. Expect to pay at least twice as much for oak, mahogany or maple as you do for pine, fir or spruce. While home improvement stores have some hardwood, you can find a greater selection direct from a lumber yard or a specialty wood outlet.

Don't Forget The Plywood

Plywood should never be left out of the equation when completing DIY projects. As the most economical of all the lumber products, pound-for-pound, plywood typically delivers more coverage than most lumber products. Plywood comes in many different types and grades.

  • For indoor utility applications, such as garage shelves, use standard A/C plywood, which has one smooth, relatively knot-free face (the A side) and one rougher, more blemished face (the C side). 
  • For finer projects, or when using plywood in place of solid hardwood, such as for a tabletop that you'll edge with hardwood strips, use hardwood plywood: the highest grades use hardwood for all of the plywood's layers; lower grades have only hardwood face veneers. 
  • Plywood for outdoor use is made with waterproof glue and may or may not have pressure-treated wood. The highest exposure rating is "Exterior," followed by "Exposure 1" and "Exposure 2," in that order. 

Centering on Softwoods

The softwood category typically consists of hemlock, fir, spruce and pine -- known as conifer or cone-bearing evergreen trees. Generally speaking, these varieties are interchangeable, and so similar in application and cost that they are marketed together as hem-fir, hem-fir-pine, or spruce-fir-pine.

Softwood Lumber Grades

Most DIY projects don't require that you use top or prime grade wood. Basic utility projects require only common or standard-grade lumber. When shopping for two-by-fours, the cheapest options are "common," "standard, "utility" or "construction grade." These are fine for non-load-bearing applications. When strength is important, look for "Select Structural," "No. 1" or "No. 2" grades.

Get Picky

Common and standard grade lumber is not perfect. Examine each board for straightness by sighting along its length. Discard boards with distinct bows or cups in the middle. Go through the pile and hand select the pieces you want -- everyone does it. Chose only straight pieces with as few knots as possible. Reject those that are cracked, split, twisted or warped.

Buy Big

Lumber and supply stores typically don't stock all sizes of lumber, and when they do stock special sizes, it's priced accordingly. You don't always need thick, wide lumber if you're building smaller items like boxes and crates or frames for shelving. Purchase and rip standard two-by-fours or two-by-sizes in half lengthwise with a table saw to produce smaller or custom sizes that cost less because you're doing the cutting.

Nominal Versus Actual

Most softwood lumber is sold in nominal -- or name only sizes. Common two-by-fours measure 1 1/2-by-3 1/2-inches, which is an actual measurement. Nominal sizing is used for most softwood. For example, two-by-sixes actually measure 1 1/2-by-5 1/2-inches, and four-by-fours measure 3 1/2-by-3 1/2-inches.

Skip the Studs

You might not always need lumber that's 1 1/2-inches thick. Lumber yards and dealers typically stock 3/4-inch-thick softwood lumber for specialty projects. Pine, fir, spruce and -- even though it's technically a hardwood -- poplar, is a top choice for economical, light-duty structural lumber.

Hardwood Lumber

Species Selection

Hardwood species selection is mostly a matter of personal preference. The differences in hardness and density are typically not significant enough to make a difference. Generally speaking, the prices of hardwood lumber are comparable to the various species to a certain extent, but expect to pay more for exotic species such as teak or mahogany than you would for more common species such as oak, ash or maple.

Hardwood Grades

Hardwood grading systems are similar to softwood. Prime quality hardwood is graded "FAS" defined as firsts and seconds. Use it when quality counts. Lower grades of hardwood are marked "No. 1 common," or "No.2 common;" use these grades of wood as a cheaper alternative to FAS lumber.

Use hardwood lumber for furniture and specialty projects such as china or buffet cabinets, curio cabinets, display cases or any project that requires pleasing aesthetics and quality wood grains.

Two Ways to Buy Lumber

Lineal Softwood

Softwood lumber is typically sold per lineal foot, which actually works out to the individual board's length. For example, an 8-foot, two-by-four is sold as an "eight-footer," which is based on its lineal measurement.

Board Foot Hardwood

Hardwood boards may be sold by the piece, in the same way as softwood lumber, or they may be priced by the board foot. The latter is more common when the material comes in random widths. A board foot measures 1-by-12-by-12 inches, or 144 cubic inches. To calculate board footage, multiply the board's width times the thickness times the length (in inches), then divide the result by 144. For example, a board that's 3/4 inch thick, 8 inches wide and 8 feet long is approximately 4 board feet (0.75 x 8 x 96 = 576; 576/144 = 4).

Lumber is sold with two different pricing systems: softwood typically sells per lineal foot, while hardwood is sold by lineal foot or by board foot.

Break it Down

  • Draw a project plan based on hardwood or softwood selection. Make a cutting list of all the lumber needed for the project. Take the list to a lumber yard.
  • Match the lumber grade to it's purpose. If it's structural in nature, purchase structural lumber. Use prime grades for aesthetics, common grades for structural.
  • Determine the thicknesses and length needed. Purchase wider, longer pieces for economy and cut them down at home. Purchase precut lumber for smaller projects.
  • Use plywood for economy when designs allow it. Use fir plywood for most DIY projects. Use hardwood plywood for cabinets and furniture.