DIY Lumber and Sheet Goods Guide

Most construction projects will make use of lumber and sheet goods like plywood and particle board for the bulk of the job. From wall framing to furniture making this page offers examples of the most commonly available materials that will satisfy most requirements. See Wood Joinery and Wood Working Tools for more carpentry help.

Lumber:

Use for framing and trim molding. To choose a good piece of lumber look for straight timbers with no twists. Site down the length of the board while holding one end up to your eye and letting the other rest on the floor. Look down both planes, the edge and the face. A view of the edge of a board (the thinner side) will reveal any warping in the wood. The face of the board will show any twisting. Reject any boards that are not straight. Using a warped or twisted board will result in an inferior finished project.

Dimension Lumber:

Smooth finished timbers used for framing walls and ceilings. These include 2x3's 2x4's, 2x6's, 2x8's, 4x4's, etc. The sizes stated are nominal and not exact. A two by four, for example, is actually 1 ½ by 3 ½ inches. Lengths typically found at the local home store are eight, 10, 12, 14 and 16 feet. A lumber yard will have longer pieces.

Finish Lumber:

These are smooth surfaced boards in nominal sizes of 1x2 to 1x12. Common uses include built–in bookcases, door and window casings, baseboards, exterior siding, cabinet doors and furniture.

Furring Strip:

This is a rough-cut piece of lumber. Nominal sizes are 1x2 or 1x3. Used frequently for furring walls and ceilings for the addition of a new wall material such as paneling or drywall.

Grade:

A system for determining the quality of wood. Smooth, straight pieces of wood with no knots or other imperfections are graded A. Grade B has minor flaws such as small knots. Grade C has more flaws and so on. Plywood graded A–B, B–C and C–D have one side that's better than the other.

Molding:

Finish lumber with a decorative profile cut on one or more edges. Used for trimming walls, furniture and cabinetry.

Nominal Size:

This is the stated size of lumber. The actual size is a bit smaller. When measuring and cutting use the actual size for accuracy.

Rough Cut Lumber:

Lumber cut at the sawmill will have a rough finish. Most of this lumber is surfaced on all four sides to smooth it before it is sold. Some of these boards will be sold as they are with the rough finish, this is true with some furring strips.

Surfaced Lumber:

Boards planed to create a smooth surface such as with finish lumber. Surfaced 4 Sides (S4S) indicates that a board has been planed on all four sides.

Timbers:

These are large pieces of lumber used for posts and pole buildings. Sizes commonly available at local home stores and lumber yards are usually 4x4's and 6x6's. These sizes are nominal, the actual size will be about ½ inch smaller. 4x4's can be improvised using two 2x4's nailed or screwed together.

Sheet goods

Sheet goods are manufactured by gluing sawdust, chips or thin sheets of wood together to form large pieces. For example, particle board is made by gluing sawdust together to form a thick sheet. Sheets are available in 4'x8' sizes. Smaller pieces are also available from home stores that cut the larger sheets for the convenience of their customers.

The project will determine the material grade. Plywood, for instance, comes in various grades depending on the smoothness of the finish. Lower grades of plywood are used for sheathing and sub–floors. Smooth hardwood plywood is used for furniture and cabinetmaking.

Finish Plywood:

Smooth finish sheets of hardwoods including oak, maple, and birch and softwoods like pine. Grades A–B, A–C and B–C are used for cabinets, furniture, doors and shelving.

Hardboard:

4'x8' sheets. Manufactured by gluing paper thin sheets of wood together. Used for furniture backing and drawer bottoms as well as peg boards.

MDF: Medium Density Fiberboard:

High quality hardboard used to make furniture and cabinets with a painted finish. Comes in 4'x8' sheets with thickness of one eighth to 1in. Also used to make trim molding by forming the molding profiles on one side, in lengths of up to 16ft.

Particle Board:

Sheet material manufactured by mixing glue and sawdust. Used for counter tops, underlayment and laminated to make inexpensive furniture. Not meant for exterior use.

Plywood Sheathing:

Grades C–D and C–D exterior. Comes in 4'x8' sheets. Used for sub–flooring and wall and roof sheathing.

T–111 Plywood:

Exterior plywood with grooves in the face for decorative effect. Used mostly for exterior siding on small outbuildings.

Wafer Board:

Sheet material manufactured by gluing chips of wood together. Used for wall and and sometimes roof sheathing. No meant for exterior use.