Building Shelving Units With Butt Joints

Stand six planks of 30-inch 1-by-12 lumber on a 30-by-1-inch edge, spaced 12 inches apart. These are the shelves of the unit and there should be 72 inches between the outside of the outer two shelves, which will eventually be the top and bottom shelf.

Apply glue to the ends of the shelves, then abut two planks of 72-inch 1-by-12 lumber on either side of the shelves. The ends of the 72-inch planks should form corners with the ends of the top and bottom shelf.

Check that all the corners created by the joint between the 72-inch side panels and the shelves are 90-degrees using a carpenter’s square and adjust as necessary.

Clamp the shelves between the side panels with F-clamps to hold the unit together while the glue dries.

Drill three evenly-spaced pilot holes through the side panels into each end of each shelf, sized slightly smaller than a 1 1/2-inch wood screw.

Secure the shelving unit together with 1 1/2-inch wood screws driven through each of the pilot holes. Stand the shelving unit upright to finish.