Choosing Lumber for Bookshelves
Q: What should I look for in lumber?
I want to cover one wall of my home office with bookshelves. How wide should the shelves be to hold a variety of book sizes, and what should they be made of?
—Harold Lloyd, Warren, Ind.
Norm Abram replies: I make my bookcase shelves 10½ to 11¼ inches wide and find that this size will handle the majority of books. But check your own collection for any odd sizes. If the shelves are going into built-in cabinets, I generally try to make them less than 36 inches long so that they won't sag.
I always build shelves with ¾-inch plywood because it's less expensive and more stable than solid wood. If the shelves will be painted, I use primed cabinet-grade plywood and glue, and nail solid ¾-inch-thick poplar to the edges. Poplar is easy to work, takes paint well, and is relatively inexpensive. On shelves that will get a clear finish, I'll usually go with an oak-, maple-, or cherry-veneer plywood, and glue and clamp the same species to the edge so that there are no nail holes to fill. Depending on the look I'm going for, the edging can be anywhere from ¾ inch to 1½ inches wide and ¾ inch thick. The wider the edging, the stiffer the shelf and the longer it can span between supports without sagging. It also makes the shelf appear thicker, a look some people prefer.
When you're looking for hardwood to rip into edging strips, you'll find oak or maple boards at many home centers. But if you want something more high-end, like walnut or cherry, you'll probably have to visit a millwork company or lumberyard that caters to woodworkers. They'll have a good selection of beautiful boards stacked flat on indoor shelves to prevent warping. You can usually get permission to pick through the stacks to find a board that suits you—just be sure to put the rest of the boards back the way you found them.