How to Build Utility Shelves

Form a 20x36-inch base frame for each shelf by gluing and clamping two 1x2 front/back rails (E) to the ends of two 1x2 side rails (F).

Secure each shelf base-frame assembly by drilling holes in the front/back rails and driving #8x1-1/2-inch flathead wood screws into each corner of the base frame.

Apply glue to the top of each shelf base frame (E/F). Position a 20x36-inch deck (D) on the top of the shelf base frame. Check for square. Realign as needed, then clamp.

Mark and drill evenly spaced countersunk holes for #8x1-1/2-inch flathead wood screws through the deck top into the base frame. Drive the screws to secure assemblies.

To avoid the aggravation and wasted time of having to adjust work that's out of square, check for square every step of the way.

Use a carpenter's square to check the ends of boards for square before and after cutting. Use a try square to check the corners of a miter joint and the ends of smaller boards, as well as for squaring a table saw blade to the table or a portable circular saw blade to the saw plate.

Diagonal measuring is one way to check for square on a four-sided assembly, such as a face frame or bookcase. Use a tape measure to find the length diagonally from one corner to another. Then measure diagonally between the other two corners. If both measurements are exactly the same, the assembly is square.